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This month, we'll take a close look at Apogee Instruments' new MQ-500 quantum (PAR) meter and sensor with improved spectral response. The MQ-500 meter is a handheld device, with a water-proof sensor connected with a cable about 2 meters in length. It is battery operated and has data-logging capabilities. It is said to favorably compete with the more expensive PAR meters and sensors due to a 'blue-enhanced silicon photodiode and custom optical filters' within the light sensor. This sensor is advertised to better report light output from LEDs. Does it? Does it offer any advantages? To answer this question, we'll pit the Apogee instrument against the gold standard of PAR meters - the Li-Cor LI-1400 meter and LI-192 sensor. And, finally, why should I own a quantum meter?
Late addendum to this article: I received word from Chris Madsen at Apogee designed a quantum meter especially for underwater use (that is, aquarium or aquaculture use). This device (dubbed the MQ-510) has the same features as the MQ-500 quantum meter. Its measurements of photosynthetic photon flux density are corrected for the immersion effect. It uses the same sensor tested in this article. See Figure 1.
Although I had been a marine aquarist since the 1960's, my 'scientific' pilgrimage began in 1991 with the purchase of a quantum meter. It is believed that at the time I purchased the quantum meter from Li-Cor Biosciences, I was the only hobbyist to use such a device to measure light intensities within a captive reef (although a few were in the hands of professional aquarists such as Pete Mohan at SeaWorld Ohio).
The trend at that time was geared towards various (often pricey) gadgets and little attention was paid to measuring or monitoring light intensity, something that was said to be very important in the successful husbandry of many coral reef invertebrates. Yet, the amount of light was not quantified and was merely referred to as 'low' or 'high' intensities. It seemed that much work needed to be done in the lighting arena, so my attention turned to works published in scientific journals. References to light intensities reportedly received by corals, other photosynthetic invertebrates, and marine algae in these journal papers used terms I was quite unfamiliar with, such as photosynthetically active radiation (PAR) and photosynthetic photon flux density (PPFD), compensation & saturation points, and so on. This was in the days before effective search engines, and literature often had to be obtained through inter-library loan services or visits to university libraries. Through quite a bit of effort, a message emerged - understanding the lighting requirements of photosynthetic plants and animals would require a substantial investment in specialized equipment. To this end, I purchased the 'quantum meter' and submersible sensor from Li-Cor Environmental in Lincoln, Nebraska, USA to the tune of about $1,500.
Over the course of a few years, the price of quantum meters dropped substantially but these less expensive sensors were not as accurate as those meters costing 10x as much. Today, this situation has changed. Apogee Instruments' recent introduction of their MQ-500 quantum meter with improved spectral response is the latest in a line of improved instruments.
Before continuing, perhaps it is best to familiarize ourselves with some of the technical jargon used in this and other articles.
Books have been devoted to this subject but we'll briefly review terminology used by botanists, phycologists (scientists studying plants, algae and photosynthesis) and coral reef biologists. Photosynthetic organisms require a minimum amount of light. When the amount of light causes photosynthesis to produce the amount of oxygen required to meet the organism's respiratory rate, then the compensation point has been reached. Lighting should, at a very minimum, meet the compensation point. Compensation Points vary, but it is generally agreed that light intensity should not drop below 100 µmol·m-²·sec-1in any non-shaded area in a reef aquarium. After the compensation point has been met, the rate of photosynthesis will be proportional to the amount of light, but only up to a point. When increased lighting does not increase the rate of photosynthesis, the saturation point has been achieved. Generally, light intensities of 200 - 400 µmol·m-²·sec-1are acceptable and will produce high rates of photosynthesis (as well as triggering desirable reflective and fluorescent colors in corals). Exceeding the saturation point wastes expensive energy and could over-heat an aquarium. Greatly exceeding the saturation point could be harmful but natural mechanisms are in place. The 'pressure-relief' valves of photosynthesis are called xanthophyll cycles, where excess energy can be shunted away from the photosynthetic apparatus in a process called dynamic photoinhibition. If the abilities of these xanthophyll cycles are not sufficiently protective, chronic inhibition occurs. Chronic photoinhibition can reduce the rates of photosynthesis and, if allowed to continue, can cause permanent damage to the coral host and photosynthetic symbionts. In extreme cases, over-lighting can cause a great reduction (or almost total loss) of either photopigments found in zooxanthellae (such as chlorophylls a & c2, peridinin, etc.) or expulsion of zooxanthellae (in a process called bleaching). Bleaching can result in death of the coral.
Sensor Size: 22.5mm diameter by 35mm tall (0.886" x 1.38"). Size matters! It is an important consideration when the purchase of a quantum meter is being contemplated since reef hobbyists are often working within a relatively small space filled with animals easily damaged by a bulky device. While this new sensor is slightly larger than the older Apogee sensor, it is much smaller than Li-Cor's. See Figure 3.
Software can be downloaded here: www.apogeeinstruments.com/downloads
This software is available for both PC and MAC versions at no additional charge.
See Figure 4 for an example of data obtained through the data-logging feature.
An interesting tool that data logging makes available is that of a summation of light falling upon a coral or another photosynthetic organism during the entire photoperiod. This is known as the Daily Light Integral or DLI. DLI is expressed as Moles Photons per Square Meter Per Day (mol photons·m²·day1.) The MQ-500 will perform this function. The best analogy I've heard is that which compares light particles (photons) to rainfall. While knowing instantaneous PPFD can be of great value it is comparable to counting the number of raindrops per square meter per second. The concept of the total number of raindrops (inches per day) is what DLI describes for photons. See here for details of DLI for Hawaiian corals: http://www.advancedaquarist.com/2013/12/lighting
It is well established that proper lighting is very important in the husbandry of aquatic photosynthetic organisms (corals, Tridacna clams, plants and algae). Too much lighting is wasteful and expensive, and it might tend to overheat smaller aquaria resulting in the use of a chiller or another water-cooling device. Too much light can also trigger dynamic photoinhibition (through conversions of a number photosynthetic pressure-relief valves involving xanthophylls). Worse, continued use of excessive lighting can cause chronic photoinhibition, where host and symbionts expend energy towards repair of photo-damage instead of other things such as growth or reproduction. In worst cases, photosymbionts such as zooxanthellae and zooxchlorae are killed, or expelled by their hosts in a process known as bleaching.
On the other hand, under-lighting will force the host/symbiont to consume energy reserves until they are completely expended. In this extreme case, due to extremely low photosynthetic rates, the animal will perish unless feeding (heterotrophy) can make up for the losses. Bear in mind, that increased feeding could result in detrimental water quality issues.
Many hobbyists obsess over calcium, magnesium, or other chemical concentrations, perhaps because the recommended values are well-established and are inexpensive to monitor. Lighting, on the other hand, is a more complex subject. In addition, it requires an investment in a PAR meter. But these facts should not discount the importance of knowing how intense the light fields are within your aquarium.
Apogee claims its full spectrum sensor can accurately determine the output of light-emitting diodes (LEDs) that generally have narrow spectral bandwidths. I tested several light sources and compared the results obtained with Apogee and LICOR sensors (in air). Note that measuring the intensity of a single point-source LED can be tricky (aquarium LED fixtures use multiple LEDs unlike most of the LEDs tested below.) I built a jig to hold the sensors and exercised reasonable care in making these comparisons, however, the measurements would likely have been a little closer if I had used an integrating sphere. With that said, there are the results:
|Light Source
|Li-Cor (rounded)
|Blue/White LED Combo
|Feit Blue
|Dark Blue
|Dark Blue
|Deep Blue
|Light Blue
|Sky Blue
|Dark Green
|Feit Green
|Light Green
|Light Orange
|Dark Orange
|Underwater (blue LED)
Details on the spectral characteristics of some of these lamps can be found here: http://www.advancedaquarist.com/2016/8/aafeature
As I have suggested, a PAR meter is a good investment for a hobbyist. If the purchase price is out of reach, perhaps your local aquarium club can purchase one and lend it to members.
I am impressed with the performance and price of the MQ-500 quantum meter. So much so, that I will regulate use of my Li-Cor LI-1400 quantum meter/ data logger and submersible sensor for low light work (such as moonlight) or very high light intensity (exceeding the Apogee's maximum reporting of 4,000 µmol·m²·sec1. To the best of my recollection, there has been only one instance where I needed a meter that could measure higher than 4,000 µmol·m²·sec1 - this was in measuring the output of a Fusion sulfur lamp where the output could exceed Li-Cor's maximum measurement of 20,000 µmol·m²·sec1).
In closing, I have listed below 11 Reasons to Own a PAR Meter:
And finally, for insights on the types of zooxanthellae and their hosts, see here: http://www.advancedaquarist.com/2016/2/aafeature
Contact Information: Apogee Instruments, Inc. 721 West 1800 North, Logan, Utah 84321 USA Phone: (435) 792-4700 Fax: (435) 787-8268 Web: apogeeinstruments.com
Light-emitting diodes (LEDs) have come a long way since simply being used as an on/off indicator on coffee makers. Technical improvements have boosted their light outputs, making them usable as automotive headlamps, street lamps, area lighting, and, naturally enough, aquaria lighting.
I first tested a LED array for possible aquarium use in 2000, and submitted the results for publication. That article was rejected on the grounds that cutting-edge technologies of that time (metal halide and fluorescent lamps) were just fine, and there was no need to consider 'wild-hair' lighting thank you very much! A few years later, I would test the first commercially-available LED unit specifically designed for aquarium use (PFO's Solaris.) This creating quite a bit of controversy with some rabidly vocalizing their disdain for this 'new' technology.
Today, one would be hard pressed to see anything but LEDs being used while making the rounds of a local frag swap or reef aquarium tour, and light-emitting diodes are firmly accepted. And with this acceptance, prices have fallen dramatically. It would only be a matter of time before novelty LED lamps would make their way into product inventories of retailing giants such as Home Depot and others.
This article will examine the spectral characteristics and light intensity of 7 lamps I recently purchased at the local Lowe's and Home Depot home improvement stores. These are a 5000K LED made by Cree, Incorporated (Durham, North Carolina), a 'blue' one made by Philips Lighting North America (Somerset, New Jersey), green by Feit Electric (Pico Rivera, California), and several (purple, yellow, and red) marketed by Home Depot (Atlanta, Georgia), and an interesting remote-controllable lamp capable of producing 15 different colors (Crayola, Easton, Pennsylvania.) All have a E26 medium mogul base, making them compatible with almost all lighting fixtures that accept standard incandescent or mogul-base compact fluorescent lamps. Prices of the Home Depot and Lowes' lamps (Hawaii prices) are about $7.00 each while the Crayola 16-color, remote control lamp is about $10. Since prices are low and availability shouldn't be much of an issue, use of these lamps could make for some interesting DIY projects.
Are the spectral characteristics suitable for illuminating planted or reef aquaria? Do they produce enough light?
We'll begin our observations with results of testing performed on the Philips' blue LED lamp.
Upon first seeing this lamp, I wondered if its blue housing was simply a marketing device to make recognition easy, or if the blue globe filtered a broad bandwidth to make it appear blue. Although I can't speak for Philips' marketing personnel, it would be apparent upon completion of testing that the LEDs contained in this lamp do produce more than just blue light although wavelengths of 400 - 510 nm compose about 77% of emitted light.
Table 1. Spectral components of the blue LED.
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Color perception can vary among individuals. To compound the issue, violet light is often confused with purple light - the former being a pure color, while purple is a combination of red and blue light. I could not tell by simply looking at the light emitted by this device exactly what color it truly was. Testing revealed very little violet light was produced, and the light is properly marketed as 'purple' since its output is a combination of blue (66%) and red (12%) with the remainder scattered among 7 other bandwidths.
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
To my eye, this lamp appears yellow although most of the emitted light is in the orange portion of the spectrum.
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
There is truth in advertising - this lamp produced light almost entirely in the red portion of the spectrum.
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
For the do-it-yourselfer, this lamp offers some interesting possibilities. First, it is capable of producing 16 distinct colors, if only one at a time. Further, it is dimmable (in four steps - 'low', 'medium', 'high' and 'very high') through use of a remote control device. Though of limited interest to aquarists, it can cycle through all colors in 'smooth' and 'strobe' modes.
Crayola's Multi-Color LED Remote Controller:
The hand-held controller offers various functions. It can turn the lamp on and off, dim the lamp in four steps, choose among 16 colors, 'flash' mode cycles the lamp through its colors in 1 second intervals, 'fade' mode ramps lamp intensity from high to low in four seconds and then changes color and repeats, 'strobe' mode acts as 'fade' mode does, but intensity is ramped incrementally in 3 second cycles. Although the directions state 'smooth' modes alternates color in 5 second intervals, my remote simply repeated 'flash' mode. Four wattages are listed for each Crayola color - one for each power setting.
We'll now examine the different colors this lamp can produce and their respective intensities.
Crayola Red:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Orange-Red:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Dark Orange:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Light Orange:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Yellow-Green:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Dark Green:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Light Green:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Sky Blue:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Light Blue:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Blue:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Dark Blue:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Deep Blue:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Ultra Blue:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Purple:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola Pink:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Crayola White:
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
|Violet (400 - 430 nm)
|Blue (431 - 480 nm)
|Green-Blue (481 - 490 nm)
|Blue-Green (491 - 510 nm)
|Green (511 - 530 nm)
|Yellow-Green (531 - 570 nm)
|Yellow (571 - 580 nm)
|Orange (581 - 600 nm)
|Red (601 - 700 nm)
Rates of photosynthesis is dependent upon both spectral composition and intensity. Of the lamps tested for this article, only the Cree 5000K lamp produced a PAR value of over 60 (with the lamp 6 inches from the sensor.) Three (Feit 'green', the 'purple' lamp from Home Depot, and the Philips 'blue') produced PAR exceeding 10 µmol·m²·sec. The Crayola multi-color lamp produced 5 µmol·m²·sec or less in any color combination. See Figure 51.
For hobbyists looking for a do-it-yourself project for a small coral reef aquarium, a combination of the Cree 5000K, Feit Green, Home Depot Purple, and Philips blue should produce enough light for a shallow tank containing animals requiring low amounts of light.
The Crayola lamp might be useful for producing a 'mood' in an aquarium. It is interesting that the Crayola lamp produces 16 distinct colors while containing only three differently colored LEDs peaking at 460 nm (blue), 526 nm (green) and 630 nm (red.) This clever color-mixing while employing various wattages is a good study in color production.
Spectra were measured with an Ocean Optics USB2000 spectrometer and OceanView software. Data were exported to a proprietary MS Excel program for further analyses. Light intensity was measured by an Apogee Instruments' MQ-200 quantum meter. Wattages were gathered through use of a Kill-A-Watt meter (P3, International.)
Tunze (pronounced Tune-zah) Aquarientechnik is a well-known German manufacturer of a number of aquarium products, including propeller pumps. This month we'll review their Turbelle nanostream 6020 and 6040 pumps. These devices are rather unique in the respect that they use semi-hemispherical deflectors to direct flow from vertically-mounted motor/propeller assemblies. This feature allows the pumps to be compact in size making them suitable for smaller aquaria. I should note that the deflector is removable which allows a wider flow pattern. They differ in their controllability - the 6020 operates at a set speed (and hence a set output) while the 6040 utilizes a controller that allows a number of operational modes. Like most prop pumps nowadays, the submerged pump motor and propeller assembly is magnetically coupled to an external magnet. Transmission of vibration to the aquarium wall is reduced through use of 4 silicone dampeners and reportedly makes for a very quiet operation.
Tunze advertises some impressive output flow for such small pumps (they are less than 17 cubic inches in volume.) Are the advertised flow outputs accurate? Are these pumps really quieter than those of Tunze's competitors?
Before presenting test results, let's examine Tunze's advertised specifications:
This pump operates at one pre-set speed only, and the US model operates on 115 volts at 60 hertz. Tunze advertises its output to be approximately 660 US gallons per hour (or about 2,500 liters per hour) and recommends it for use in aquaria ranging in size from 10 to 65 US gallons (see comments in the Conclusions section below.) Power consumption is said to be 4 watts.
Other specifications are:
Water Flow Output: Output (expressed as gallons per hour, or gph) of the 6020 was determined by measuring water velocity at the discharge and this information was plugged into the formula discussed in the 'Testing Procedure' below. The 6020 was found to generate water movement of 1.4 feet per second, which equates to about 510 gallons per hour.
Water Velocity: As mentioned, it is common practice to rate (and judge) pump performance by its output (gallons per hour.) In practice, this metric is of limited use - if corals were capable of caring, they couldn't care less about 'gallons per hour'. It is water velocity that matters. Without going into a lot of detail, water motion (velocity) allows for transfer of substances (such as oxygen, nutrients and trace elements) through a stagnant layer of water that surrounds allow submerged objects. This stagnant water is called the 'boundary layer.' The thickness of the boundary layer is inversely proportional to water velocity. If water velocity is low, and the boundary layer becomes too thick, a coral (or any sessile invertebrate) could be starved for dissolved substances necessary for health. Water velocity on a natural coral reef is usually 6 to 8 inches per second (0.5 to 0.67 feet per second or 0.34 - 0.45 miles per hour.) Velocity in spur and groove channels, shallow reef flats, or during storm conditions can be much higher.
Power Consumption: Testing revealed the 6020 pulled 4.5 - 4.6 watts and 0.04 amps at 121.5 volts.
Sound Level: Noise can be a major distraction from an otherwise magnificent aquarium, whether it's from a slurping overflow, vibrating metal halide ballast, or vibration generated by a pump. Tunze has a taken a rather unique approach in minimizing noise from their pumps. The pump assembly is attached to the internal magnetic coupler with silicon vibration dampeners.
Visually, the nanostream 6040 appears very similar to the 6020. It is the about the same size, uses propeller technology, is magnetically coupled to an external magnet, and so on. But there are major differences. A rectifier converts 120-volt alternating current to 12-volt direct current which allows a controller to vary speed of the 6040's pump and pulse flow duration (Note: Tunze recommends the power supply assembly not be controlled by a third party timer.) It is possible to run the pump using a photovoltaic system (8-12v input.) A battery backup is also possible. In this case, Tunze recommends a device called 'Safety Connector' (part #6105.50; ~$55 US.) - it is an automatic transfer switch that switches from a 120v power source to a 12v battery.
These are the 6040's specifications per Tunze:
The 6040 Controller: Once a novelty, pumps controlled by a device with programmed features are becoming commonplace. The controller for the 6040 offers a variety of features. These options include variable speed (and hence increased water velocity and flow), pulse or oscillating flow (adjustable from 2 to 10 seconds, with an auto-adjust feature. Note: Tunze recommends the pump shaft/impeller be in a vertical position with the flow deflector removed.) The 'fish feeding' mode shuts the pump down for 10 minutes, after which it re-starts automatically. There is quite a bit of other engineering within the controller. The pump will shut down if input voltage exceeds14v (a likely indication that the rectifier has failed. Tunze cautions that input voltage exceeding 24v will destroy the controller.) The 6040 will shut down if it runs dry. A cradle is supplied for wall mounting the controller. See Figure 3.
Options: Moonlight simulation is possible when using a moonlight diode (#7097.050; about $35 US). This allows a simulated lunar cycle of 29 days going from new moon to full moon and back. The pump will then go into night-mode operation. The controller can be daisy-chained to a second controller and pump with optional cable (part #7092.300; ~$11 US) - this will allow pulses of increased flow simulating tidal changes or enhanced oscillating flow. A third controller/pump can be connected to the setup through use of a y-adapter (part #7090.300; ~$19 US.)
Water Flow Output: Figure 4 shows water velocity at various distances from the discharge of a 6040 pump at full speed.
The 6040 as a 'Wavemaker': Using the 6040 as a wavemaker requires positioning the pump with discharge (without the deflector) pointing straight up and about 2 to 4 inches (5 to 10 cm) below the water surface. There is an 'Auto Adjust' feature that incrementally ramps the pump run time upwards. When a wave of sufficient size is generated through resonance frequency, the hobbyist can enter settings in the controller's non-volatile memory by simply pressing a button.
Aquarium size definitely matters in this regard. One 6040 in a 55-gallon aquarium produced waves about 1 inch (25 mm) high, but did not produce a sweeping action to suspend particles on the bottom of the tank. In a 20-gallon tank, the device produced a wave approximately 3 inches high that was able to move negatively buoyant particles around on the bottom. See Figure 5. On the other hand, the pump produced waves that sloshed out of a 5.5-gallon tank and literally rocked a coral head weighing about 1 pound (454 g.)
Power Consumption: Power consumption is often an ignored long-term cost and should be considered before purchase of any aquarium electrical appliance. See Figure 6 for power consumption of the 6040 at various settings.
Automatic Shut-off: The 6040 will automatically shut down if it runs dry or if the impeller rotation is blocked, and it will restart automatically 20 seconds after a correction is made. The pump also has a thermal overload.
Sound Level: Comments made about sound generated by the Turbelle nanostream 6020 (above) also apply to the nanostream 6040. While the pumps are very quiet (practically silent) in continuous run mode, there is some noise made by the pump itself when it is in the wavemaker mode. With this said, sounds of turbulent water will likely mask this sound. See Figures 7 and 8.
Heat Transfer: Any electrical device will generate some heat, and these pumps are no exception. The question is then not of 'if', but to what degree these devices will transfer heat. As we know, high temperatures are an enemy of corals so heat transfer becomes a critical issue. A simple experiment was devised to test for heat - a 5.5-gallon (38 liter) aquarium was filled with water, a 6040 pump was installed and allowed to run at full speed for 48 hours. Temperature was then compared to water held in a 10-gallon aquarium. Figure 10 shows the results.
Maintenance: Tunze advertises the 6020 and 6040 to possess an undescribed 'self-cleaning system' but recommends a disassembly and thorough cleaning using a soft-bristle brush and soaking in vinegar to dissolve mineral buildups at two year intervals. It has been my experience that cleaning should be performed more often (every couple of months or so) when the device is used in hard water situations (such as African cichlid and reef aquaria.)
Warranty: Tunze guarantees the unit to be free of defects in material or workmanship for a period of 24 months after the date of purchase. Water damage to the 6040's controller is excluded.
Retail Price: The 6020 retails for about $40 US while the 6040 costs ~$140 US plus tax and shipping (if applicable.)
Customer Service: These pumps were broken in for a few weeks before testing, but before that began I disassembled them for a thorough cleaning. Upon assembly I discovered I had somehow lost misplaced a part. I contacted Tunze USA for a replacement via email on a Sunday night, received a reply early Monday morning that the part was on its way. I give Tunze an A+ for customer service.
Conclusions: Given the small size of these pumps, Tunze has clearly produced them for smaller aquaria. I've seen excerpts of Tunze's cut sheet in retailers' advertising that claims these pumps are suitable for tanks up to 130 gallons. This could well be the case if minimal water motion is required (such as a seahorse tank.) However, close examination reveals Tunze recommends more than one of the 6040 pumps for larger aquaria (retailers - read the owner's manual!)
Both pumps consumed slightly more power than advertised according to the testing device I used, if only by 1.7 watts.
Testing suggests the 6020 moved less water than advertised, but this might be due to the large size of the water motion sensor (its rounded shape is larger than the size of these pumps' discharge. The Marsh-McBirney sensor is designed for testing streams and rivers where large scale water motion is fairly consistent.) In any case, the 6020 produced a discharge velocity of 1.4 feet per second, which equates to a respectable 510 US gallons per hour.
In the opinion of the author, Tunze has done a disservice to itself when rating the 6040 by only its water movement (gallons per hour.) While moving 1,080 US gallons per hour is impressive, it is this pumps ability to produce waves through resonance that is important. While testing, this pump was found to produce waves capable of moving a coral about the size of a 16-ounce water bottle. See a close up photo of this coral's polyp expansion in Figure 11.
Thoughtful engineering is apparent through both pumps. From the noise/vibration dampening of the silicon isolators to the option-packed 6040 controller, Tunze continues its tradition of quality in design. To my knowledge, these pumps' vertical drive shaft/propeller combined with a flow deflector is unique. This combination makes for a small footprint which is ideal in smaller sized aquaria and allows the pump to be partially (or perhaps fully) hidden behind rockwork. The ability to direct the water flow with the deflector is an interesting concept. The small size of the 6020 and 6040 might allow just one more coral to be placed in a nano-reef.
A word of caution - the coupling magnets supplied with both pumps are quite strong and could easily pinch the fingers of a careless hobbyist.
In closing, I purchased these pumps for use in small aquaria used in experiments for my 2016 MACNA project. They have met my expectations, and exceeded them in a couple of respects.
And last, but not least, when I needed some assistance, Tunze USA responded in a timely manner.
Ratings: Both pumps have similar ratings (as marked on the pumps themselves.) These include:
'IP68' Perhaps an explanation is in order: 'IP' stands for 'ingress protection', while 6 = Totally dust tight, and 8 = Protected against prolonged effects of immersion under pressure. Tunze states these pumps are rated for that pressure seen at a depth of 1 meter of water.
'RoHS': Tunze has obtained the Restriction of Hazardous Substances certification (RoHS - sometimes called the 'lead rule' but also restricts products' content of lead, chromium, etc.), as well as the European 'CE' mark.
Maximum Temperature Rating: Tunze states these pumps are good to go at temperatures up to 95ºF (35ºC.)
Testing Procedure: For measuring flow at various distances, these devices were installed in a 55-gallon aquarium (48"x19.5"x 13.5"; 122 x 49.5 x 34cm) filled with freshwater. Testing of pulse mode was performed variously in 5.5-gallon, 20-gallon, and 55-gallon aquaria.
Water velocity was measured with a FloMate 2000 electronic water velocity meter (Marsh-McBirney, Frederick, Maryland, USA). The sensor was located about 1/16" away from the central point of the pump discharge with the deflection hood removed. To arrive at gallon per hour figure, velocity measurements were plugged into this formula:
Power consumption was determined through use of a Kill-A-Watt electrical monitor (P3 International.)
Noise, as decibels, was measured with a Spier Scientific Sound Level Pen, model #840018.
Conflict of Interest: These pumps were purchased through normal retail channels.
Water movement is perhaps the most under-rated parameter in reef-keeping. Creating proper water motion is much easier today than in the nascent days of reef-keeping with a procession of improved devices. An important step in this respect was the introduction of propeller pumps. Using propellers for model boats available in hobby shops, pumps producing high output were cobbled together by the industrious hobbyist Jimmy Chen, and these types of pumps have dominated the field ever since.
EcoTech Marine is a company located in Allentown, Pennsylvania, USA, and has, for a number of years now, produced many products intended for aquarium use. Several of their products are pumps using propeller technology. This month, we'll take a look at one such pump - the MP40 with the QuietDrive driver. It is advertised to be quieter and produce more flow than the previous MP40 model. How do these claims hold up under close scrutiny?
These are the advertised specifications:
These items are included with the MP40wQD:
The MP40's driver is capable of running the pump motor in various modes of operation. Selecting the program is easy - Press the Mode button on the controller to scroll through various options (operational mode is indicated by color of the Control Dial.) Once the proper mode is indicated, press the Set button (this will either allow selection of options in EcoSMART or Random Modes, or speed and frequency set points in other modes.)
Programming in the controller includes:
Gallons per hour is the standard for determining pump output. In coral research, and for practical aquarium applications, it is a meaningless metric. Since gallons per hour is calculated using flow velocity and area, it is apparent that, at a given output, increasing the area of the pump discharge reduces velocity. As such, a pump with a large discharge area might reduce velocity to the point of uselessness. Coral researchers almost never discuss flow in gallons per hour - it is velocity that is most often mentioned. I offer information on 'gallons per hour' simply to determine if the MP40's output is reasonably close to that advertised. See Figure 3.
Water Velocity at Various Power Settings As discussed earlier, water velocity is the true metric we should use when determining the sizing of a pump for an aquarium. See Figure 4.
Water Velocity at Various Distances As stationary benthic organisms, corals rely on water currents for a number of reasons. It is well known that many coral species can grow and develop skeletal shapes particular to water motion. Generally, corals from low velocity areas maintain an open architecture while those found in areas of violent water movement will grow in dense compact forms. I have measured water velocities on coral reefs on the leeward side of the Big Island of Hawaii in normal (not stormy) weather and have found them to be in the 6 to 8 inch per second range. Compare this to velocities created by the MP40 pump (Figure 5.)
EcoTech Marine advertises that the MP40/QuietDrive combination delivers more flow than its predecessor, and this is true although, under the conditions of testing (described below) the output is about 7% less than listed in the owner's manual. See Figure 6.
I was surprised to see the new MP-60 working harder in Gyre mode than in maximum Constant mode (amount of work being determined by wattage drawn.) The water velocity meter I have takes about 30 seconds for measurements to stabilize. Since the Gyre mode has episodes of high and low velocities, I was unable to determine how much water was actually being moved. Figure 7 is a projection and it shows this pump will move about 5,000 gallons per hour (compare this to the advertised '4500+ gallons per hour.')
Noise is the enemy of a tranquil scene - something most hobbyists strive for when building a captive reef. It is advertised that the QuietDrive is, well, quieter than the older model MP40. Sound levels were measured with a sound meter at a standardized distance from the pump motor. See Figure 8.
Power usage is an on-going, and often ignored, cost. Power consumption was determined through use of a device capable of measuring the metric for work: watts. See Figure 10.
It should not be surprising that the mode using the most power (and moving the most water) is the one running constantly at full pump speed. Less obvious is the fact that the Lagoonal mode moves more water than the Reef Crest selection (though Reef Crest will have episodes of higher water velocity.) The NTM (Nutrient Transport Mode) and Reef Crest selections move, overall, about the same amount of water although the former uses a pulsing action.
Figure 11 demonstrates power consumption at various pump power settings (these in Constant Speed mode at top speed setting.)
I was curious if the MP40 was more efficient at a given operational speed. As Figure 12 shows, this propeller pump delivers more gallons per watt consumed at lower speeds.
I often learn things the hard way, sometimes by either not reading directions or ignoring them. Take it from me, do these things!
Cleaning: EcoTech Marine recommends cleaning the wet side assembly every 6 to 8 weeks, or more often as necessary. Disassembly is easy - simply twist the discharge nozzle counter-clockwise to remove it. Clean with a soft bristle brush (an old toothbrush works fine) to remove fouling growths. Calcium deposits are best removed by soaking in vinegar. Avoid strong acids as they might damage pump components.
Wireless Control: Optional wireless control is available for those EcoTech Marine devices (VorTech pumps, Radion LED lighting) so equipped with wireless capability. The ReefLink device allows communication with computers, iPads, etc. through cloud-based EcoSmart Live.
Warranty: EcoTech Marine warrants for 1 year defects in material or workmanship.
Price: At the time of this writing, the retail price of the MP40 was $349.99 US, plus tax and shipping. This represents a price reduction of about 25% from the previous price of $445.
The MP-40 with QuietDrive delivers as advertised with some caveats. Under conditions of testing conducted, the pump will deliver 5,000 plus gallons per hour when in Gyre mode, but this amount of flow is periodic. In addition, the amount of work performed (as measured by watts consumed) is higher than advertised. Maximum observed GPH when is Constant Mode at the highest setting was about 4,200. The pump motor/propeller assembly operates quietly (when alignment is proper) and it is indeed quieter than the previous model, however, there is a low humming noise generated, especially when the pump is ramping up to desired speed.
The recent price reduction of this pump certainly makes it more competitive in a field now crammed with manufacturers. If you're in the market for a propeller pump in this class, the new MP-40 with QuietDrive might be worthy of your consideration.
Contact Information
The MP40 device was installed in a 55-gallon aquarium (48"x19.5"x 13.5"; 122 x 49.5 x 34cm) filled with freshwater.
Water velocity was measured with a FloMate 2000 electronic water velocity meter (Marsh-McBirney, Frederick, Maryland, USA). The sensor was located about 1/16" away from the central point of the pump discharge. To arrive at gallon per hour figure, velocity measurements were plugged into this formula:
Flow (Gallons per Hour) = Velocity (inches per second x 60 x 60) x Discharge Area (in square inches) / 231 (cubic inches per gallon)
Power consumption was determined through use of a Kill-A-Watt electrical monitor (P3 International.)
Noise, as decibels, was measured with a Spier Scientific Sound Level Pen, #840018.
Certifications: EcoTech Marine has obtained the Restriction of Hazardous Substances certification (RoHS - sometimes called the 'lead rule' but restricts products' content of lead, chromium, etc.), as well as the European 'CE' mark.
Conflict of Interest Statement: This device was purchased through a normal retail channel.
Newcomers to the reefkeeping hobby may not be familiar with the many questions surrounding the issue of lighting in the early days of the hobby. Then, we assumed nature to be the ideal model for lighting - light intensity mimicking sunlight had to be better, blue light seemed to promote coloration, and so on. Today we understand that light that is too intense can be detrimental to zooxanthellae and the host coral. Simple experiments using PAM fluorometry can quickly and easily confirm that zooxanthellae do not have unlimited adaptive responses to high amounts of light.
Experiments examining the effects of spectral qualities on coral growth are not as easily done. Spectral quality for each lamp must be analyzed, of course, in order to understand its effects. Ideally, the experiment utilizes an aquarium that houses all target corals at the same time in order to ensure water quality parameters are standardized (which is virtually impossible when experiments are conducted during separate time frames.) Light intensity must be standardized (an expensive PAR meter is required since this is not easily done when using a 'hobby grade' PAR meter.) And these experiments are time-consuming. With that said, I'll detail the procedure next. If you're not particularly interested in these minutiae, skip to the Results and Discussion section below.
Corals tentatively identified as Porites lobata were maintained in a 240-gallon aquarium (8' x 2' x 2') See Figure 2. A 100-gallon Rubber Maid sump housed a protein skimmer (ETS model 800, driven by a Danner Mag 9.5 centrifugal pump), a reactor containing granular ferrous oxide for phosphorus removal (Two Little Fishies), and a return pump (Danner Mag 7.5.) The protein skimmer's effluent traveled through a small plastic basket filled with the macroalga Chaetomorpha and illuminated by a LED strip light (Build My LED). Together, this equipment maintained reactive phosphorus and inorganic & organic nitrogen species to extremely low levels. Three fishes (two Yellow Tangs and a Chevron tang) were housed in the aquarium.
The 240-gallon aquarium was illuminated by 7 LED strip lights (identified as Solar- Max, 2-6500K, 2-20,000K, and 2-Custom strips; all from Build My LED) placed approximately 20 inches apart. Light intensity was adjusted through use of dimmers (Build My LED) and maintained at an intensity of 128 µmolm²sec through the duration of the procedure. This light intensity is sub-saturating and was originally measured with a Li-Cor LI-1400 data logger and submersible quantum sensor. These measurements were compared to those obtained by an Apogee PAR meter and correction factors were determined. Since this experiment involved light measurements in tight quarters, the small size of the Apogee sensor was a plus; hence it was used periodically to ensure 'proper' light intensity was maintained. Photoperiod was 12 hours on/ 12 hours off.
Spectral qualities were determined with a fiber optic spectrometer (USB2000, Ocean Optics) and their software (OceanView™.) The spectrometer's patch cord gathered light reflected from a diffuse reflectance standard (99%, Spectralon.) Results were exported to a proprietary Microsoft Excel program for further analyses. Note: The charts showing spectral data in 10nm increments were not corrected for the instrument's dark signal.
Water motion, an important parameter since it can affect coral respiration, was homogenous throughout the tank through use of a 'Wave Generator' (Tunze Wave Box™.) Although a digital water meter (FloMate 2000, Marsh-McBirney) was available, it was unable to accurately measure pulses generated by the Tunze device. Hence, water motion (~3"/sec; oscillating) was determined visually by measuring movement of floating pelletized fish food.
One coral specimen was divided in equally sized fragments by cutting 1" diameter nubbins from the colony with a 1" diamond hole saw. These were allowed to heal for several days, and then glued to fired ceramic plugs (Boston Aqua Farms) with SuperGlue. A Sharpie™ permanent marker had been used previously to make identification markings on each ceramic plug. These plugs/corals fit neatly into egg crate jigs built to maintain positions under the LED strip lights. Ten corals each were maintained under each spectrum for a period of 75 days. Corals/plugs (plugs gently brushed to clear any fouling growths and entire surfaces blotted dry) were weighed every two weeks or so through use of an analytical balance (Sartorius, resolution of 0.0001 gram - see Figure 3.) Corals were rotated under their respective lights after each weighing in order to minimize any minor differences in spectral quality.
Chlorophyll content was also determined in milligrams/square meter by a fiber optic chlorophyll meter (CCM-200, OptiScience), and this will be discussed in a future article.
Four distinctly different spectral signatures were generated by LED strip lights. These were identified as Solar Max (warm sunlight), 6,500K (cool sunlight), Custom (visually similar to the spectrum of metal halide lamps marketed as ~14,000K), and 20,000K (very blue.) See Figures 4 through 11.
The Daily Light Integral (DLI) is the sum of the number of photons falling upon a given surface area during the entire photoperiod. PAR meters report the number of photons falling on a given surface area in one second. This is similar to counting the number of raindrops falling in one second, when we're really interested in the total amount of rainfall. This is what DLI reports, and it is reported as molphotonsm²photoperiod. DLI is easily calculated:
DLI = 128 µmolmsec * 60 seconds/minute * 60 minutes/hour * 12 hours/photoperiod ÷ 1,000,000 = 5.53 molphotons
To put this in perspective, corals in a shallow Hawaiian tide pool receive a DLI of about 22 molphotons during a February photoperiod of 11.5 hours, and about twice that during a cloudless summer day.
Survival rates were 100% for all corals, and all exhibited growth. See Figures 12 - 15.
Figure 15 shows the average weight gain of the 4 groups (n = 10 each.)
All LED luminaires promoted coral growth over the course of the 75 day procedure and although there were differences, they were not statistically significant.
The results ask more questions than the procedure answered. Since others have demonstrated statistically significant growth rates under differing light regimens at similar light intensities (Wijgerde and Laterveer, 2013), and effects of spectral quality on photophysiology (Wijgerde et al., 2014), why did these corals not exhibit significant differences? There are many possibilities. Perhaps the light intensity chosen (128 µmolm²sec) was simply too low and barely exceeded this zooxanthella clade's compensation point (the Clade is assumed to be C15, found almost exclusively in Pacific Porites. However, Wagner et al. (2010) found Hawaiian black corals from depths up to 396m (~1,300 feet) where light levels were too low to support photosynthesis, raising the possibility that the association between the host and endosymbiont might not be mutualistic.) Another possibility is flow-related. It is possible the rate of flow (estimated to be ~3"/second) was not sufficient to minimize the momentum boundary layer and thus created a nutrient gradient where a starvation situation of sorts existed.
The take home message suggests that low light intensity does not significantly affect growth rates of this shallow-water Porites under the conditions of this experiment.
Experiments designed to answer questions raised by this procedure are now underway.
I wish to thank Build My LED (www.buildmyled.com) for supplying the LED strip lights used in this experiment.
It is difficult to overstate the importance of water m0tion in a reef aquarium, and the last decade or so has seen many advances in technology of water moving machines. One of the latest devices, Maxspect's "Gyre Generator" is a pump that has re-thought how to move water in an aquarium. Unlike propeller pumps, this machine uses two centrifugal fans (sometimes referred to as 'squirrel cage' fans or pumps.) A centrally located submerged direct current (DC) motor is coupled to these fans. Guarded water intakes allow intake of water, which is pushed out discharges on either side. The entire assembly is held in place by an external magnet, and a controller lets the aquarist decide on how much flow (either continuous or pulsed) as well as reversed flow. A Feeding Mode is also available for use.
The following are included:
Advertisements for this device claim 'virtually no dead spots' in an aquarium. Can the Gyre Generator live up to this claim? Are there any drawbacks to its use? Is it power-hungry? This article will investigate these and can assist you in deciding if this device is a good investment. The model tested is the XF150.
Water moving devices can be intrusive in appearance so size really does matter. The Gyre Generator is compact in size and isn't instantly noticeable in an aquarium, but perhaps more important, its relatively small size allows it to fit nicely into aquaria only 12 inches wide.
These are the dimensions and specs:
The controller supplied with the XF150 is a remarkable device - its compact size belies its abilities. Further, it is simple to program and can be mastered in a few minutes. There are only three buttons. The first is an off/on switch, the second is for determining mode of operation (constant flow, pulsed flow, and so on), and the third is for setting mode parameters, such as pump speed while using a control dial (complete with indicator LEDs.) 'Normal' rotation or 'alternating' rotation is indicated by LED lights as well. See Figure 2.
A mounting cradle for the controller is included. The generous electrical cord length allows the controller to be mounted away from the aquarium (a good thing since the controller is not waterproof.) The mounting cradle can be mounted with a small piece of double-side tape (included) or with small screws (available at hardware stores.)
The controller for the XF150 allows several options to the hobbyist: Constant Speed, Pulsed Flow, and Alternating Flow. Pump speed (rpm) is adjustable in each of these modes. There is also a "Feeding" mode.
As the mode's name states, this option operates at the pump at a constant speed (which is adjustable on a scale of 1 to 10, with 10 producing the most flow.) See Figure 3 for gallons per hour moved by this pump at various speed settings.
Gallons per hour has been the standard for rating aquarium pumps' usefulness, although it is not particularly useful for determining application. It is flow velocity that truly matters, and for that reason testing was performed to the XF150. See Figure 4.
Visually judging water motion patterns is difficult unless special procedures are in place. A simple technique was developed for this article - fluorescent bits of plastic (illuminated by a 40-watt 'black light') were placed in the test aquarium and their motion was captured through time exposure photography. See Figures 5 and 6 for visualization of water motion patterns in the Constant Speed mode.
For those wishing to generate waves within an aquarium (see Figure 7) a mode for programming pulsed flow is available. The pump operational frequency and speed is quickly and easily set via use of the standard controller.
Using the photographic technique described earlier, Pulse Mode water motion patterns were made apparent. See Figure 8. The oscillating flow pattern seen is similar to that seen on many natural reefs.
As with any pump capable of pulse mode, hobbyists should exercise caution when making water slosh in an aquarium. The constant pressures on glued joints of a tank could result in failure of these joints after prolonged use of such a device.
Alternating Flow Mode allows the pump to rotate in a 'forward' and 'backwards' manner. If the pump runs in this mode with the standard squirrel cage impellers (those attached to the pump straight out of the box), the forward mode will create laminar flow and, when in reverse, will create turbulence. The XF150 comes with a spare set of rotors (called A and B rotors; See Figure 9.) When the spare 'A' rotor is installed in the place of the original 'B' rotor, it is possible to create laminar flow with one side of the pump while making turbulent flow with the other.
The pump can be programmed to alternate flow direction every 2 minutes to 12 hours.
Feeding mode will temporarily stop the pump to allow feeding. It starts automatically after 10 minutes.
The XF150 can be disassembled in less than a minute when cleaning is required. Small particles can enter and become jammed in the rotors. Calcareous algae growths (which seem to love black plastic) could impact performance in addition to making disassembly a somewhat of a chore (the cage stabilizing arms are friction fit.) Maxspect recommends cleaning pump components every 3 months by submersing parts in a solution of one part white vinegar and one part water.
Based on my experience, I would suggest that hobbyists make alignment marks between the rotor cages and motor housing. Also note that the cages are marked 'A' and 'B.' I made marks on mine using a colored Sharpie™ permanent marker. Since the impeller housings are adjustable (the discharge flow can point up, down and every point in between), it is easy to get them out of the desired alignment unless keen attention is paid. Simply marking the rotor housings will make correct reassembly a snap. In addition, there are rubber grommets between the distal tips of the alignment arms and the cages. These grommets can slip off, and it is easy to end up with two rubber 'caps' on the end of one arm. This is not easily apparent to casual observation since the grommets and the housing/arm are almost identical in color.
Cost of operation is an important consideration. Power consumption (watts) was tested using a commercially available electrical monitoring device. Maxspect advertises the pump to pull 50 watts at maximum power - the test showed a maximum of 50.1 watts - very close indeed.
Power usage (in another test) was also tested over the full range of power settings. See Figure 10.
Watts consumed by the pump while creating the maximum wave size (about 4 inches) in pulse mode averaged 21 watts.
Pump output (defined as gallons per hour) per watt is at its highest at low speed settings (see Figure 11.) Slippage of the rotating squirrel cages is not possible since the pumps' drive shafts' connections are notched. I suspect the squirrel cage rotors are the culprits, but this should be of little concern to most hobbyists as the output is impressive.
Noise generated by any aquarium device (water pump, lamp ballast, overflow, etc.) can distract from the beauty of any aquarium. Sound levels ('ambient' and 'pump on') were measured with a decibel meter. See Figures 12 and 3 for levels, and Figure 14 for a decibel scale.
Some advertisements on the internet claim the XF150's outside coupling magnet is sufficient for glass up to ¾" thick - which is true if an optional 'reinforcement magnet kit' is purchased. The Owner's Manual says the standard magnet is recommended for glass up to ½" thick.
The Maxspect Gyre device was installed in a 55-gallon aquarium (48"x19.5"x 13.5") filled with freshwater.
Water velocity was measured with a FloMate 2000 electronic water velocity meter (Marsh-McBirney, Frederick, Maryland, USA). To arrive at gallon per hour, velocity measurements were plugged into this formula:
Flow (Gallons per Hour) = Velocity (inches per second x 60 x 60) x Discharge Area (in square inches) / 231
Power consumption was determined through use of a Kill-A-Watt electrical monitor (P3 International.)
Noise, as decibels, was measured with a Spier Scientific Sound Level Pen #840018.
Maxspect has made a real effort to get their product to conform to US and European standards. This device has an Underwriter's Laboratory (UL) stamp of approval for the US and Canada. It also has the Restriction of Hazardous Substances certification (RoHS - sometimes called the 'lead rule' but restricts products' content of lead, chromium, etc.), as well as the European 'CE' mark.
Maxspect warrants this product to free of defects for 1 year from date of purchase, and will repair or replace the device at its option. Warranty work for many customers is performed at CoralVue's U.S. facility in Slidell, Louisiana.
A complete line of spare parts is available for order online at: www.coralvue.com/parts
At the time of this writing, Gyre pump parts began on page 20. Items likely to show wear after long periods of use are the impeller bushings, which are available for $3.00 each at the time of this writing. If the Alternating Flow Mode is not used, the extra set of volutes and bushings (supplied, and shown in Figure 9) are essentially spare parts.
Maxspect advertises that each Gyre device is tested in water before leaving the factory.
The manufacturer's suggested retail price is $299.00 US.
The Maxspect Gyre XF150 is a well thought-out product. Its compact size belies its high performance, which is on par with some propeller pumps costing much more. The retail price is reasonable as far as high performance controllable pumps are concerned. Operational cost (based on electrical usage) is modest. Its operation is relatively quiet in the Constant Speed Mode. In Pulse Mode, the noise generated by ramping up of the DC motor is noticeable.
The flow pattern created by the Gyre pump is unlike that of any propeller pump on the market. The pump's water discharge runs almost the entire width of the device, which creates a wide, high velocity zone of water movement. This laminar zone, if unimpeded, can be up to ~24" in length before becoming turbulent in nature. Still, a horizontal gyre could be created throughout the tank under the conditions of testing and no 'dead spots' were noted.
The Maxspect Gyre Generator is not the most powerful pump on the market nor is it the least expensive. However, its unique flow can create wide water patterns unlike any other device currently on the market and it is worthy of your consideration for purchase.
For Product Update Information visit Maxspect's website: www.maxspect.com
How time flies. It has been seven years since I wrote a product review on the first commercially available LED lighting system (PFO's Solaris). That article created a lot of controversy, and blogs & billboards were alive with opinions on LED lighting. Since then, the detractors from the ability of LEDs to maintain the health of corals in captivity have been proven wrong, and this form of lighting has gained wide acceptance within the hobby. And, as popularity grows, prices continue to fall.
This month's review is that of the EverGrow Nova A4 LED luminaire customized with LEDs selected by Barrier Reef Aquariums of Seattle, Washington.
I have accumulated a number of LED units in my bone yard over the years, and failures are usually due to fan or power supply failures. Disappointed by the longevity of some LED luminaires on the market, I decided some time ago to discontinue LED product reviews unless the product met certain criteria, such as:
This unit meets all these, and this article will relay general observations as well as results of lab testing.
The Nova A4 luminaire has an adjustable spectrum - there are two control channels. One controls white and 'color' LEDs and the second adjusts the royal blue LEDs. The LEDs in this unit possess some interesting spectral characteristics.
The Spectral Power Distribution (SPD) shows the LEDs' outputs are almost exactly as advertised.
420nm Violet
Violet light is important in the promotion of photosynthesis as well as corals' production of fluorescent and non-fluorescent proteins. See Figure 1.
450nm 'Royal Blue'
These LEDs produce light peaking at ~443nm. See Figure 2.
470nm Blue
These 4 blue LEDs produce light peaking at 469nm. See Figure 3.
520nm Green
Two green LEDs produce light peaking at 513 - 515nm. See Figure 4.
660nm Red
Two LEDs in this fixture produce red light at ~660nm. See Figure 5.
White LEDs
The spectral characteristics of the two types of LEDs (6,500K and 12,000K) are fairly similar, and Figure 6 is typical of these.
As would be expected with a luminaire utilizing many blue LEDs, the spectral is skewed towards the violet/blue portion of the spectrum. See Figure 7. Figure 8 shows the composition of the light in a pie chart, and Table 1 shows this information numerically. Figure 9 and Table 2 shows spectral characteristics in 10 nanometer increments.
Several modes of operation are available for this light. For those light-hungry plants and animals, the 'Sunny' mode is the ticket - these LEDs can generate light intensity exceeding sunlight (when the PAR sensor is placed just a couple of inches from the light.)
The 'cloudy' mode decreases light intensity by about 40% (compared to the 'sunny' mode.)
The 'moonlight' mode activates 3 blue LEDs to simulate moonlight (with a PAR value of less than 1 µmol·m²·sec.)
A 'manual' mode allows dimming of light in two channels (one channel is for the 21 LEDs producing light peaking at 450nm and the other dims all others.) This feature allows an infinite tuning of spectral characteristics and light intensity.
Power consumption was measured in 3 operational modes. Power draw by the built-in control panel was determined as well (no lights or fans on). These are the figures:
The LEDs in this luminaire are apparently under-driven. See Figure 11 for a graph of these numbers.
Light distribution patterns are rarely, if ever, uniform across a given area, and light produced by this fixture is no exception. See Figure 12. These measurements were taken with a Li-Cor Li-1400 quantum meter and Li-192 quantum sensor at a distance of 3.5 inches below the fixture. Recall that maximum sunlight intensity is ~2,000 µmol·m²·sec - this fixture approaches this value under these circumstances.
Light penetration into the water column is important and this fixture does an exceptional job in this respect. See Figure 13.
A remote control device is included with the Nova luminaire. It provides a convenient means of programming the fixture, as well as an off/on switch. The white buttons on the controller are phosphorescent - they slightly glow a greenish color in conditions of low light. This thoughtful touch makes the controller easy to use when programming even in low light conditions. See Figure 14.
Serious hobbyists might use a PAR meter to determine light intensity when installing this fixture. Few will have the luxury of a 'lab grade' quantum meter, such as that made by Li-Cor Biosciences and will instead use a less expensive device (such as that made by Apogee Instruments). I compared the measurements obtained through use of these meters, and found that the Apogee meter (when in 'electric light' mode) reported a value ~15% higher than those made with the Li-Cor. See Figure 15.
This LED fixture offers impressive performance at a reasonable price. The customized spectrum produced by the LEDs is interesting in that it is not the standard mix of blue and white LEDs. The addition of violet light (at 420nm) and green (at ~515nm) provides a visually balanced spectrum (as well being able to promote photosynthesis. The photopigment peridinin found in zooxanthellae absorbs green light - this is the reason zooxanthellae are brown). The light is intense enough to allow the fixture to be positioned well above the aquarium, where it is less likely to be subjected to water splashes and salt spray. However, the housing is made of a ferrous material and a protective coating of clear polyurethane or car wax (or both) is recommended for protection. Barrier Reef Aquariums recommends one of these fixtures for every 20 inches of aquarium length (approximately).
The amount of light produced by this fixture is remarkable and can certainly meet requirements of the most demanding corals. In fact it can easily exceed their needs and care should be used when mounting it above the aquarium. Figure 13 shows the PAR values at various depths (the fixture is 6.5 inches above water level). Most corals need only 200 - 300 µmol·m²·sec in order to saturate photosynthesis (where increasing the amount of light will not increase the rate of photosynthesis.) Mounting the fixture at least a foot or so above the aquarium is probably a good idea but monitor the corals for any signs of distress. Using the dimming feature is another option. Remember that an Apogee PAR meter reports values about 15% higher than that of a 'lab grade' quantum meter.
At the time of this writing, the retail price is $299.99 US, and includes shipping to addresses in the continental US.
Orders can be placed on Barrier Reef Aquariums' website: http://www.barrierreefaquariums.com/
Questions can be addressed by phone: (425) 277-7670 or by e-mail: firstname.lastname@example.com
If you're in the Seattle area, visit them at: 1717 NE 44th Street, Suite A, Renton, Washington. They're behind the Impressions Dentistry office.
Barrier Reef warrants that EverGrow's products will be free of defects for a period of 2 years, in either workmanship and/or defective components. Failures due to abuse, moisture, and improper ventilation are not covered. Proof of purchase is required.
Barrier Reef will repair the unit in-house, or, as an option, supply parts for repair by the owner. I wondered how difficult a replacement of a fan or power supply would be, so I opened the unit up for a look (see Figures 16 and 17.)
Upon inspection, I determined replacement of a cooling fan or power supply is something any handy aquarist should be able to do. All that is required is a Phillips head screwdriver, wire stripper (a single edge safety razor blade will do in a pinch), and electrical tape.
Ease of repair of LED lighting has been a pet peeve of mine, and is a reason I refused to write product reviews on them for quite some time.
This product complies with the following standards:
ISO Certification (International Organization for Standardization): Based in Switzerland, ISO (International Organization for Standardization) is an international quality management system. Companies can achieve ISO9001:2008 certification when they meet certain standards. Compliance helps ensure constantly reliable products.
CE: A marking required by the European Commission for many products marketed in the European Economic Area, or EEA. This marking means the product conforms to safety, health and environment protection standards of the European Commission.
RoHs is the abbreviation for Restriction of Hazardous Substances Directive (in electrical and electronic equipment) in the European Union (EU). Lead, mercury, cadmium, chromium (hexavalent), polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) content are regulated by RoHs.
The Shenzhen Sanxinbao Semiconductor Lighting Co., Ltd was founded in 2006, and its operations are ISO 9001:2008-certified. Their products comply with CE standards and the RoHS Directive (see above.)
Photosynthetically Active Radiation (PAR) measurements were determined through use of two quantum meters (LI-1400 data logger and underwater quantum sensor (Li-Cor Biosciences, Lincoln, Nebraska, USA), and a MQ-200 and underwater sensor (Apogee Instruments, Logan, Utah, USA).
Light attenuation was determined with a Li-Cor underwater quantum sensor (calibrated for 'air' and 'water' where appropriate) mounted on a specially built jig. The sensor was lower incrementally into a black polyethylene drum filled with freshly mixed artificial sea water.
Spectral characteristics were made by a fiber optic spectrometer and related software (model USB2000 spectrometer and SpectraSuite software, Ocean Optics, Dunedin, Florida, USA).
Power consumption measurements were made with an electricity usage monitor (Kill-A-Watt meter, P3 International, New York, New York, USA).
A question I commonly ask during a presentation is 'How many own a PAR meter'? I am often pleasantly surprised to learn that light measurement is coming more common among reef hobbyists. Still, those using a PAR meter are in the minority - which I find interesting. Undoubtedly, those not making light measurements will fret over calcium concentrations or pH levels, while leaving light intensity levels unchecked. This is interesting still - excessive light is expensive, beginning with the purchase of the lighting fixture and continuing with operational costs and peripheral expenses, such as water chilling. More importantly, excessive light can inhibit coral growth and, in extreme cases, kill them.
For those unfamiliar with these light measuring devices, Photosynthetically Active Radiation (PAR) is those wavelengths between 400nm and 700nm (violet to red light) that promote photosynthesis. A PAR meter reports the number of photons (light particles) within this bandwidth of light as Photosynthetic Photon Flux Density (PPFD), in units of micromole photons per square meter per second (µmol photons·m²·sec, or simply µmol·m²·sec). Older literature might report PPFD in units of microEinsteins per square meter per second, or µE·m²·sec. No conversion is necessary as 1 µmol·m²·sec = 1 µE·m²·sec. Maximum PPFD near the equator at noon on a clear day is ~2,100 µmol·m²·sec.
For years, PAR meters (or more properly, quantum meters) were used by only research scientists. To my knowledge, one of the first public aquariums to use one was SeaWorld Ohio. It was an aquarist there, Pete Mohan, through his writings in FAMA magazine, who introduced me to the concept of PAR measurements within an aquarium. My interest (obsession) lead to a purchase of a Li-Cor quantum meter and underwater sensor in the mid 1990's (at the tidy sum of $1,500. I recently upgraded to a Li-Cor 1400 data logger and underwater sensor at the cost of almost $3,400.) In any, case Apogee Instruments (Logan, Utah, USA) would release a few years later a much more affordable PAR meter costing only $200 or so. This would revolutionize the way hobbyists measured light intensity within their aquaria. These meters have gone through several iterations, and this review will focus on the latest from Apogee Instruments - the MQ-200 Quantum Meter. This device has been upgraded considerably over the older model Apogee meter I own.
These specifications are current at the time of this writing:
The Daily Light Integral is the total amount of light (or Photosynthetic Photon Flux Density, or PPFD) falling on a given area during the entire photoperiod. The best comparison is to compare PPFD to rainfall. An instantaneous PPFD value (the number of photons falling on a given surface area in a given amount of time) is equivalent to the number of raindrops falling on an equal area and time. We would find a weather report presenting rainfall as number of raindrops falling on a square meter per second to be practically useless. We are more interested in the total amount of rainfall reported in inches or centimeters. The same is true for light - we should be interested in the total number of photons in a given photoperiod.
The MQ-200 is capable of storing 99 measurements, either in a manual entry mode or automatic data logging. In the log mode, a measurement is made every 30 seconds, and these are averaged every 30 minutes and stored in memory (for a total of 48 measurements stored every 24 hours. Hence, the meter can store about two days' worth of measurements. The device will also calculate the Daily Light Integral for each 24-hour period.) Data is easily copied to a clipboard and then pasted into MS Excel™ or other spreadsheet. The software sorts data as 'Sample Data' (instantaneous measurements), '30-Minute Average' (logged data), and 'Daily Totals' (DLI).
The basic package for the MQ-200 meter includes the meter, cable, and submersible probe (as a unit), a plastic protective cap for the sensor, and directions for downloading the user's manual. The battery is also included, making the meter ready to go straight out of the box.
Although the meter is capable of data logging, an optional, special USB cable and Apogee's proprietary AMS software is required. The software is available for download from Apogee's website and takes only a few minutes to obtain and install. If you are running a 64-bit system, the software is provided on a flash drive along with the special USB cable (a standard USB cables will not work. The meter's output is UART - Universal Asynchronous Receiver Transmitter - and must be changed to USB by a converter within the cable). The data is saved in a CSV format and can be exported to a spreadsheet (such as MS Excel) or a word processing program (such as MS Word).
A Sensor Wand is available, but it is recommended for use in only freshwater. See below for details on constructing a saltwater-safe wand for less than ten dollars.
Since Apogee's sensor wand is not recommended for uses in saltwater, hobbyists are forced to improvise. Fortunately, the solution is simple and inexpensive to make with parts available at any well-stocked hardware store. I made the wand described here for $8 US. This wand can easily be broken down for compact and easy transport.
Parts List:
Assembly is quick and easy. Glue one magnetic to the bottom of the sensor and another to one of the 90 elbows (make sure magnetic polarity is correct so they attract). Do not glue the elbows to the pipe - this will allow angling of the sensor in tight spots. A couple of options exist - the pipe can be marked in increments with a Sharpie™ so as to allow an estimation of depth. If the depth of an aquarium is deep, and the length of the wand is long and makes for inconvenient transport, it can be divided into sections and a ½" CPVC coupling can be used to friction fit the pieces together. See Figure 3.
Apogee offers a limited warranty to the original purchaser for 4 years from the date of shipment from the factory. The warranty does not cover abuse, unauthorized disassembly, damage due to fire or flood, shipping costs, etc. Apogee products are manufacturer in the USA.
At the time of this writing, Apogee's MQ-200 Quantum Meter retails for $379. A USB cable (capable of data conversion from UART to USB) and flash drive (containing software for 64-bit systems) is available for an additional $49. The Sensor Wand - recommended for freshwater use only - is $49 (interestingly, Apogee does not list the fully extended length of this telescopic wand.)
The Apogee MQ-200 Quantum Meter offers many advantages to aquarium hobbyists. The meter is relatively inexpensive (as quantum meters go). The submersible sensor is small and allows measurements to be made in tight spots.
It is welcomed news that Apogee has increased the meter's range from 1,999 to 3,000 µmol·m²·sec. This will allow work in strong sunlight as well measurements of intense lighting system (such as high-wattage metal halide lamps and some of the LEDs using narrow angle focusing lenses.)
Older model quantum meters from Apogee had a rotary switch to toggle between 'electric' and 'sun' modes. While this design was reliable, it was a potential entry point for water and salt spray. The new MQ-200 is improved in this respect. Meter functions are changed via a waterproof keypad. See Figure 4.
The meter's port for the USB cord has a protective plastic plug in it, but I found it is easily dislodged through even normal handling. To protect it, I simply placed a small piece of electricians tape over it to hold in in place.
Battery replacement is more convenient than in older Apogee models. Battery replacement in older meters required removal of the entire back cover that exposed internal electronics. The battery in the MQ-200 is contained in a housing apart from the internal electronic guts, and requires removal of only one Phillips head bolt from the protective cover to access it. The coin type battery is available at almost any hardware or drug store.
The back of the meter has a threaded insert, allowing the meter to be secured with a bolt to a tripod or other support device when conducting field work.
Programming the meter for automatic data logging is simple and is accomplished with just a couple of keystrokes. While data export is quick and easy via the UART/USB cord, only the last of recorded datum shows the time. This is easily overcome; of course, I was just a little surprised that each point did not show the time it was recorded.
Hobbyists should note that this Apogee will underreport radiation from lamps producing violet and red (above ~650 nm). Metal halide lamps' readings are usually closer to the true value than LEDs producing narrow bandwidth light at 405nm (violet) and any LED with a peak higher than 650nm.
Perhaps I'm just old fashioned, but I prefer an owner's manual in hardcopy form instead of one I have to download and print. The manual is 19 pages of information on several Apogee Quantum Meters (MQ-100, MQ-200, MQ-301, MQ- 303 and MQ-306).
All things considered, the Apogee MQ-200 Quantum Meter is a valuable device for serious hobbyists. In a day where thumbnail sized coral fragments are selling for close to $1,000, advanced aquarists would do well to invest in this meter.
Apogee Instruments, Incorporated
721 West 1800
North Logan, Utah, USA 84321
Phone: (435) 792-4700
Fax: (435) 787-8268
This product was purchased through normal retail channels.
The promise of LED technology to be able to offer an infinite range of color and controllability is finally reaching the point of reality. LEDs have to potential of offer unparalled controllability allowing users to control a wide range of features such as - spectrums, color temperatures, ability to vary these throughout the day, add special effects such as cloud covers and lightning, tight integration with modern aquarium controllers, wi-fi and internet based control. Additionally, the ability to upgrade using single platforms can provide users with a path to address rapid obsolescence as well as the ability to tweak the fixtures to the application. The new "high end" LED fixtures such as the Ecotech Radion Pro, GHL Mitras, and AI Hydra are perfect examples of these capabilities.
Continuing in the same vein as my previous LED lighting tests, this article presents data on light intensity and spread along with spectral plots for these new LED fixtures. Table 1 presents a list of the LED lighting fixtures reviewed in this article. Each of these was tested using the same set up as my previous reflector tests, using a 3'X3' grid with a spacing of 3" in the X,Y direction. The fixtures were centered on this grid, and PAR was measured as PPFD (Photosynthetic Photon Flux Density) in micromoles/m2/sec using a LICOR 1000 data logger and a LI-192SA underwater cosine corrected sensor calibrated for both air and water. The data logger was set to average 5 readings for each data collection point. The data was imported into Microsoft Excel for analysis and the data was plotted to display the light spread and intensity at various distances. 4 plots of the data with 2 plots at each distance were generated showing:
The spectral distributions were measured using the Licor LI-1800 spectroradiometer. The spectral data was collected from the various LEDs and normalized such that integrated light output (spectral irradiance) between the wavelengths of 400-700 nm was 100 Watts/m2. Data was collected at full power output for the individual channels of light control (e.g., Blue, white) along with data with ALL LEDs on at full power. The data was normalized so that the total irradiance was at 100 Watts/m2 over the wavelength range 400-700 nm. The various LED color outputs were then scaled by the same scale factor to allow of determination of the contribution of the various LEDs to the full output. The results are plotted as a Spectral power distribution plot. The fixtures were tested for light spread and intensity at 24"and 30", unless otherwise noted. Power draw was measured with a Kill-A-Watt meter.
|LED Fixture
|Ecotech Marine
Radion Pro
Mitras 6100
Mitras 6200
|Aqua Illumination
|LED Fixture
|Ecotech Marine Radion Pro
|AI Hydra
|GHL MItras 6100HV
|GHL Mitras 6200HV
|# of LEDs
|Type and LED groups
|White: 8 Cree XT-E Cool White (5w each)
Red: 4 Osram Oslon SSL Hyper Red, 660nm (3w each)
Yellow: 2 Osram Oslon SSL Yellow, 590nm (3w each)
Green: 4 Cree XP-E Green, 520nm (3w each)
Blue: 8 Cree XP-E Blue, 468nm (3w each)
Royal Blue: 8 Cree XT-E Royal Blue, 442nm (5w each)
Indigo: 4 SemiLEDs UV, 415nm (2.5w each)
Ultraviolet: 4 SemiLEDs UV, 405nm (2.5w each)
|White: 4 Cree XT-E Cool White
Red: 2 Osram Oslon Deep Red
Green: 2 Cree XP-E
Royal Blue: 4 Cree XT-E
Blue: 4 Osram Olson Very Deep Blue
Violet: SemiLED 415nm Violet
UV: Edison Opto 400 nm UV
|White: 12 Cree XT-E cool white
Neutral White: 6 Cree XT-E neutral white
Red: 6 Osram Oslon SSL red
Hyper Red: 6 Osram Oslon SSL hyperred
Blue: 12 x Cree XP-E blue
Royal Blue: 12 x Cree XT-E royal blue
Green: 6 x Osram Oslon SSL true green
Yellow: 6 x Osram Oslon SSL yellow
Hyper Violet: 6 425 nm
|White: 12 x Cree XT-E cool white
Blue: 12 x Cree XP-E blue
Royal Blue: 12 x Cree XT-E
Neutral White: 6 x Cree XT-E
Green: 6 x Osram Oslon SSL true green
Sky White: 6 x Osram Oslon SSL
Blue White: 6 x Osram Oslon SSL
Red: 6 x Osram Oslon SSL hyperred
Hyper Violet: 6 x hyper violet 425 nm
|# of control Channels
|# of LED groups/type
|Peak Spectral Range of LEDs
|405 nm - 660 nm
|425-660 nm
|425-660 nm
|Wireless Control
|communicates wirelessly with other Radion lights and VorTech pumps through EcoSMART Live
|Wireless remote control
|communicates wirelessly with other Mitras lights and ProfiLux Controllers (with expansion card "PLM-PWC") or PC (with USB-wireless dongle)*
|communicates wirelessly with other Mitras lights and ProfiLux Controllers (with expansion card "PLM-PWC") or PC (with USB-wireless dongle)*
|Control Software
|Cloud based -EcoSMART Live
|Web based Director, MyAI cloud based
|PC based operating software
|PC based operating software
|Tethering Required for Control
|Yes - USB
|Yes - USB
|Yes - USB
|Control Features
Sunrise Sunset
|Over Multiple lamps
|Over Multiple lamps
|Over Multiple lamps
|Cloud Simulation
|Sweeping over multiple lamps
|Sweeping over multiple Lamps
|Sweeping over multiple Lamps
|Thunder Storm
|Moon Phases
|Rainy Days
LED clusters
|Led Clusters
|Replaceable LED clusters
|Replaceable LED clusters
|Air cooled with one water resistant cooling fan
|Air Cooled with one cooling fan
|4 cooling fans
|4 cooling fans
|Other Noteworthy features
|Capacitive touch exterior controls
|Remote with touch controls
|Exterior Touch LED control panel
|Exterior LED touch Panel
|Custom TIR Lenses
|Custom TIR lenses (80 deg), also available with 50 deg.
|Metal coated PET reflector, 99% total reflection 96% diffuse
|Metal coated PET reflector, 99% total reflection 96% diffuse
|L: 11.8 in.
W: 7 in.
H: 1.5 in
|L: 11.875 in.
W: 5.375 in.
H: 2.1 in.
|L: 13.38 in
W: 7.08 in
H: 1.57 in.
|L: 13.38 in
W: 7.08 in
H: 1.57 in.
|3.66lbs. (1.66kg)
|Power Consumption at Full Power
|190W (high output)
120W (high efficiency)
|190W (high output)
120W (high efficiency)
|Regulatory Compliance
|UL, CE & RoHS
* Not available in the current version tested
The Radion Pro is the latest generation of the Ecotech Radion LED series. The relevant information regarding the various LEDs and other features is summarized in Table 2. The basic Led arrangement is shown in figure 1. Figures 2 and 3 show the light distribution and the spectral outputs of the various LEDs.
The AI Hydra is the newest of the Aqua Illumination (AI) product based on the same AI Vega platform. It offers less flexibility than the AI Vega in terms of control however it still provides 7 channels of control which is more than adequate to create a wide range of colors. The LED pucks are not upgradable as they are in the AI Vega. The relevant information regarding the various LEDs and other features is summarized in Table 2. The basic Led arrangement is shown in figure 4. Figures 5 and 6 show the light distribution and the spectral outputs of the various LEDs and control channels.
The GHL Mitras are LED pendant lights from Germany. The Mitras LX platform is the basis for a wide range of LED configurations. Two of them the 6100HV and the newer 6200HV are tested here. The relevant information regarding the various LEDs and other features is summarized in Table 2. The only major difference between the 6100HV and 6200HV is in the configuration of the LEDs. All other features are identical. The 6200HV has more blue and less red whereas the 6100HV is designed to provide a fuller spectrum. Both the 6100HV and 6200HV were tested for spectral output, but only the 6200HV was tested for light distribution.
The basic Led arrangement is shown in figure 7. Figures 8 and 9 show the light distribution and the spectral outputs of the various LEDs for the GHL Mitras 6200HV and Figure 10 shows the spectral output for the GHL Mitras 6100HV.
The latest generation of LEDs with their range of multicolor LEDs and multiple channels of control offer unprecedented ability to create a wide range of colors that would suit the aesthetics of the aquarium couple with the requirements of the coral. All of these LEDs are typically programmed through software interface that allows great amount of flexibility in configuring the colors, the ability to ramp the intensity up and down to create effects such as sunrise, sunset, moving cloud covers, lightning simulation, moonlight simulation, and for some even different power settings for high output and high efficiency.
To facilitate ease of programming the colors, often the software includes preprogrammed color temperatures. This range of color temperatures is obtained by dimming some of the LEDs, which in turn leads to lower output as well as lower power consumption. For example, Figure 11, shows the various spectrums of the preprogrammed color temperatures of the GHL Mitras 6200HV. Table 3 shows the power consumption at the different preprogrammed color temperatures.
|Programmed Color Temp.6200HV
The GHL Mitras also allow the user to pick between 2 operating modes - High output and High efficiency. The difference in the output at these 2 modes is shown in table 4, and Figure 12.
|PPFD at 12.5"
|High Output
|High Efficiency
|High Output
|High Efficiency
While all of the LED manufacturers provide the power consumption data for the LEDs, the actual power draw as measured by a Kill-A-Watt meter is shown in Table 5. Figure 13, shows the spectral comparison between the different LEDs at maximum output normalized to a spectral irradiance of 100W/m2. Since all of them tend to use the same manufacturer of LEDs, the only major differences are from the composition of the LEDs used.
|Power (Watts)
|Amps (A)
|Volts (V)
|Power Factor (PF)
|AI Hydra
|Radion Pro
|GHL 6200 HV (high output)
|GHL 6200 HV (high efficiency)
|GHL 6100 HV (high output)
|GHL 600 HV (high efficiency)
Comparing the light distribution of these LEDs as shown in Figures 2, 5 and 8 are useful to provide insight into the practical use of these LEDs. At first glance it may seem like AI Hydra does not have the spread or intensity as compared to the other 2. But this is very misleading without considering the power consumption. Since all of these different LED fixtures use almost identical LEDs from Cree and Osram, the main differences in output are directly related to power consumption and numbers of individual and different LEDs and optics. The AI Hydra for example uses only 95W of power as compared to a Radion at 171W and GHL 6200HV at 208W. So, in practice you may have to use 2 AI Hydra to get the equivalent light output of the other two. At around ½ the price of a Radion Pro, using 2 AI Hydra may be better option for your application. Remember that the light intensity is additive where it overlaps. Running the lights at full output shows that the GHL Mitras has the largest distribution of light and would be suitable for the coverage of about a 3 ft square area, and hence suitable for larger tanks. The Radion Pro on the other hand, has a slightly smaller distribution than the GHL, but achieves higher intensity at the same distances. This makes it more suitable for taller tanks, or they can be mounted higher to get a larger spread.
LED lighting has come a long way and the new generation of LED fixtures is delivering on the promise of LED technology, and control features. As usual, the users need to consider their own applications to determine the best one for the situation. Hopefully this data will be helpful in making your decisions.
New LED fixtures continue to be introduced into the hobby. Specifically, there has been an increase in the number of LED fixtures providing a more fuller color spectrum with multiple channels of control, allowing the user more freedom in custom tuning the light output. Continuing in the same vein as my previous LED lighting tests, this article presents data on light intensity and spread along with spectral plots for several new LED fixtures. Table 1 presents a list of the LED lighting fixtures reviewed in this article. Each of these was tested using the same set up as my previous reflector tests, using a 3'X3' grid with a spacing of 3" in the X,Y direction. The fixtures were centered on this grid, and PAR was measured as PPFD (Photosynthetic Photon Flux Density) in micromoles/m2/sec using a LICOR 1000 data logger and a LI-192SA underwater cosine corrected sensor calibrated for both air and water. The data logger was set to average 5 readings for each data collection point. The data was imported into Microsoft Excel for analysis and the data was plotted to display the light spread and intensity at various distances. 4 plots of the data with 2 plots at each distance were generated showing:
The spectral distributions were measured using the Licor LI-1800 spectroradiometer. The spectral data was collected from the various LEDs and normalized such that integrated light output (spectral irradiance) between the wavelengths of 400-700 nm was 100 Watts/m2. Data was collected at full power output for the individual channels of light control (eg. Blue, white) along with data with ALL LEDs on at full power. The data was normalized so that the total irradiance was at 100 Watts/m2 over the wavelength range 400-700 nm. The various LED color outputs were then scaled by the same scale factor to allow of determination of the contribution of the various LEDs to the full output. The results are plotted as a Spectral power distribution plot.
|Tao Tronics
|Aquatic Life
Expert Series
The fixtures were tested for light spread and intensity at 24"and 30", unless otherwise noted. Power draw was measured with a Kill-A-Watt meter.
The Maxspect Razor (R420R M16000) is built with a very slim profile, and is one of the thinnest LED fixtures in the market. The unit tested is the M16000, based on its advertised rating of 16000K color temperature. The unit has 2 channels of control with the following LEDs arranged in the 2 channels, as shown by their specifications in Figure 1 below.
These leds are arranged in 3 sets (or clusters) with the pattern in each set as shown in Figure 2.
The power consumption as measured by the Kill-A-Watt meter is shown in the table below.
|Maxspect Razor (R420R M16000)
The Aquatic life Expert series 14" model comprises 24 Cree LED`s: 8-White XPG, 8-Blue XPE, 6-Royal Blue XPE and 2-Red XPE, arranged as shown in Figure 5. The LEDs can be controlled through the The T-Time Software which enables custom programming of the LEDs. . Included in this customization is the ability to create 18 different light color combinations, three 24 hr cycles, control cloud cover, lightning storms and lunar light. Once programmed, the Light Fixture is controlled with the handheld remote.
The power consumption as measured by the Kill-A-Watt meter is shown in the table below.
|Aquatic Life XS
The Tao Tronics has 55 3W LEDs are arranged in an array with 5 rows and 11 columns, with each column containing LEDs of the same color, with 5 columns of Blue LEDs (Total 25) in the 460-470 nm range, and 6 columns of white LEDs (total 30) in the 12000-14000K color range, arranged as shown in Figure 8. The LEDs are operated at around 2W. The controls are simple with 2 channels each allowing ON/OFF control via 2 power cords. One power cord controls the blue and the other the white LEDs as shown in Figure 9. The unit is air cooled with 3 fans..
The power consumption as measured by the Kill-A-Watt meter is shown in the table below.
|Tao Tronics
The 3 LEDs tested here, represent a wide range in light output as well as price points. Based on the data the cheaper Tao Tronic LEDs do not use any optics and hence the light measurements at 24" and 30" are quite low compared to the other 2. A light such as this only provides white and blue LEDs and is mostly suitable for shallower tanks with the LED fixtures mounted close to the top of the tanks. The Maxspect Razor is an attractively styled light with 6 different LED colors, however the control capabilities are limited to 2 channels. The power draw is fairly high at 192W even though the fixture rating is 160W. The higher power does translate into more light output than the others at distances of 24" and 30". The Aquatic Life Expert Series 14" fixture also provides 4 different LEDs that can be controlled individually through their control software that runs on a computer. Given that is a smaller fixture, the light distribution is smaller than the larger Maxspect Razor. The Aquatic Life Expert Series is also available in larger sizes. The data provided should be useful to aquarists making decisions on LED lighting for their reefs.
Perhaps the most popular metric used in evaluating the performance of aquarium pumps has been rate of flow, usually expressed in gallons or liters per hour (g.p.h., or l.p.h., respectively). However, there is more (or correctly, less) to the story. Although oceanographers and limnologists may on occasion be interested in flow rates, the metric most often reported is simply velocity (inches per second, centimeters per second, etc.).
As aquarists, we know the rate of flow from aquarium pumps depends upon many factors, including the size of the pump's discharge area (or diameter, since most pump discharges are round). Since the equation for calculating a Flow Rate (g.p.h. /l.ph.) = Area (of the pump discharge) * Velocity (or Q = V*A), increasing or decreasing the discharge area affects the velocity of the water flow exiting the pump. Hence, velocity is the most critical parameter. This is important - velocity that is too high can cause harm to sessile invertebrates' tissues. On the other hand, low velocity fails to deliver the desired effects of having a pump in the first place. This article will look at water motion based simply on velocity as tested within a relatively large home aquarium and briefly examine water velocities seen in real reefs and lagoons. Together this information will allow hobbyists to make informed decisions on pump selection and pump & invertebrate placement.
All pumps tested for this article are manufactured by Tunze Aquarientechnik GmbH (Penzburg, Germany) and are of the 'nanostream' series, including models 6015, 6025, 6045 (with a mechanical discharge adjustment), 6055, and 6095. These pumps use small electric motors connected to a propeller to move water.
Water velocity has long been recognized as an important factor on natural coral reefs and there is much valuable information available to hobbyists. The categories chosen for this article were developed by one of the more prolific researchers of coral reef water flow dynamics - Kenneth Sebens. In his 1997 work, Seben's categorized water velocities into 4 zones.
See Figure 1.
Pumps were testing in a 240-gallon aquarium (24"x24"x96") filled with saltwater at a specific gravity of 1.025. Water velocities were measured by a FloMate 2000 electronic water velocity meter (Marsh-McBirney, Maryland, USA). The meter's probe was held in place by a jig to measure water velocity on a horizontal plane at depth equal to that of the center of the pump's discharge. The jig was designed to also measure velocities on the x- and y- axes. Measurements were taken at approximately 2 inch increments on the x- and y-axes (the z-axis being fixed at one depth). These measurements were logged into MS Excel, with a surface area chart selected, and printed. Outlines of the rough flow patterns were traced, scanned, and exported to MS Paint where the different velocity zones were colored. These drawings were further enhanced in MS PowerPoint.
Velocity attenuation (weakening) charts were made using velocity data collected at distances from the highest velocity recorded (generally at the center of the pump discharge). Bear in mind that these measurements were made in a bare aquarium where no aquascaping offered obstruction to flow.
An important first step in the visualization of a pump's discharge is its basic shape in an unrestricted environment. In all cases reported here (except for the model 6045, when the throttle is positioned neat the pump's motor), Tunze pumps produce jet-like streams (as opposed to a diffusive fan-like pattern). See Figure 2.
With the preliminaries out of the way, we will begin our examination of Tunze nanostream pumps, starting with:
See Figures 3 and 4.
See Figures 5 and 6.
This pump is of a different design than the other nanostreams in that it has a sliding collar within the discharge nozzle that be moved to regulate flow. Interesting, this device has an impact on flow velocity and flow pattern.
See Figure 7.
Pump: 6045 nanostream , adjustable throttle towards discharge Maximum Discharge Velocity: 2.44 feet/sec Manufacturer Recommends for Tanks: 11 to 132 gallons Volts: 121.3 Amps: 0.10 Watts: 7.8 Hertz: 59.9
See Figures 8 and 9.
See Figures 10 and 11.
See Figure 12 and 13.
The nanostream series offers a variety of options for hobbyists. Interestingly, the pump motor's wattage does not necessarily indicate the degree of performance.
An aquarist must first determine the requirements of the captive invertebrates. This could include close observations of other aquaria and reading aquaria (or scientific) literature. An in-depth analysis of requirements is well beyond the scope of this article but general guidelines can be offered. Non-photosynthetic corals (such as the stony coral Tubastrea and soft corals of the genus Dendronepththya) will probably require very good water movement in order to facilitate feeding. Coral tentacles would show some movement - larger polyps should move as wheat in a field while smaller polyps should 'ripple' in the flow. This may require some work to find the 'sweet spot' - if water flow is too low, the coral will eventually not extend its tentacles at all (some researchers believe the energy required to keep polyps extended for food capture in low flow is greater than the energy required to keep polyps contracted, and the coral responds with energy conserving measures). On the other hand, flow that is too great may cause the coral to protect itself through polyp retraction. Bear in mind that some corals do not extend tentacles at all hours and some specialize in day (or night) feeding. Some researchers have described required water motion based on the structure and interstitial spaces of stony corals' skeletons (called the porosity index). This means a stony coral with widely spaced branches will require less water flow than a coral that has multiple, tightly packed branches. Keep in mind that water motion requirements will change as corals grow (especially some of the SPS corals such as Acropora species). And while on the subject of Acropora specimens, I have wondered if reports of branch tips losing tissue could be due to them growing into areas of strong water flow. With that said, using the information above, we can make further general recommendations.
Manufacturers often recommend minimum/maximum tank sizes for their pumps based on gallon capacity. Tunze owns an electronic flow meter and bases their recommendations on actual data; however, the type of tank (fish-only, reef, etc.) is not specified. When discussing tank sizes in this article, the following dimensions will be assumed for tanks of the following capacities:
It will be assumed that a fish-only aquarium will require the least amount of flow/velocity while a full-blown reef aquarium stocked with numerous stony corals will require the most (although the same could be said for a tank containing non-photosynthetic corals require strong water motion is required to facilitate food delivery). However, resist the temptation to utilize the largest pump available - this can result in some really odd flow patterns in an aquarium. More is not always better.
It appears that the water velocities produced by these pumps is more than adequate for the smallest aquaria applications recommended by Tunze (that is, 11 gallon size for the 6015, 6025, 6045, 6055, and 26 gallons for the 6095). For the largest aquaria recommendations (53 gallon size for the 6015 & 6025; 132 gallons for the 6045, and 264 gallons for the 6055 and 6095), the velocities seen at the most distal point possible from the discharge of the pump will be in Seben's low range of 2" or less per second). This might be fine for fish-only tanks or reef tanks where careful selection of invertebrates tolerant of low water velocity has been deliberate. More than one nanostream pump will be necessary to provide adequate circulation in larger tanks. Use of the information provided on each nanostream pump (above) should help in your decision-making process.
This information is reflective of Tunze equipment available in January, 2012.
Questions? Comments? Leave them in the Comment section below, or, for a quicker response, email me at firstname.lastname@example.com.
Build My LED is a newcomer to the aquarium lighting market. This company, based in Austin, Texas, is unique in that they offer the consumer the option of custom-configuring their lighting system. With 18 different LEDs to choose from, this allows a choice of 565,000,000 light combinations according to the website. Their lighting fixtures can also be used for horticulture, commercial and light therapy applications, in addition to aquarium lighting.
These options are currently available, and their tutorial will walk you through making your choices.
Lighting fixtures (luminaires) are available in lengths of:
Lens options allow the hobbyist to choose beam angles of:
Build My LED uses LEDs from Luxeon Rebel and Rebel ES Philips Lighting along with those made by Everlight Shuen Electronics. While Philips is a household name, the latter company may need an introduction - Everlight is based in Taipei, Taiwan and has had an international presence since 1983. Everlight is one of the 10 largest LED companies in the world. 'Shuen' is Chinese for 'shiny' or 'bright'.
A multitude of LED spectrum options are available enabling the user to select almost any conceivable color. These include:
Fifteen LEDs are installed per foot (30cm) of fixture length.
The fixture tested in this review has the following dimensions:
While Build My LED offers five beam angles to handle various lighting applications, I selected the 60 degree beam angle for my fixture.
I get many emails asking a simple question: What is the best light? Unfortunately, there is no simple answer. If we discount the highly subjective personal preferences of light quality, the answer involves doing some homework on which types of photosynthetic organisms are maintained. For instance, the light quality required for terrestrial plants differs slightly from that needed by, say, zooxanthellae. The question of showcasing the variable fluorescence found in many corals is often a consideration. I offer the following in order to briefly touch on the subject.
Ultraviolet (Max. Wavelength ~405nm): Although Photosynthetically Active Radiation (PAR) is defined as those wavelengths 400 nanometers and above, chlorophyll a absorbs wavelengths to at least 350nm (Jeffrey et al., 1997). These wavelengths will also excite fluorescence in many of the coral fluorescence proteins.
Acrylic materials often attenuate (weaken by absorption) ultraviolet wavelengths. This is not the case with the material used by Build My LED - no cutoff point is apparent at wavelengths below 380nm. Most of the radiation generated by the UV LED is in the visible range. See Figure 1.
Royal Blue/Blue (Max. Wavelength ~450/470nm): Chlorophylls found in zooxanthellae (chlorophylls a and c²) absorb blue wavelengths. Chlorophyll a (also found in terrestrial and freshwater plants) absorbs blue light at ~430nm while chlorophyll c² absorbs maximally at 450nm. These numbers shift by a few nanometers according to the solvent used to dissolve chlorophylls for testing. The accessory pigment peridinin absorbs light at a maximum of ~460nm. Chlorophyll b (found in terrestrial and aquatic plants) absorbs blue light at ~457nm. See Figure 2.
Cyan/Green (Max. Wavelength ~505/525nm): Peridinin (an accessory pigment found in zooxanthellae and associated with chlorophyll a) absorbs light at a maximum of 456nm and up to ~485nm (green-blue). This wavelength falls between the maximum produced by blue and green (or white LEDs). Cyan or green LEDs would be a good choice for those wishing to mimic a turbid coral reef environment. See comments on limits of light production by green LEDs below.
Red (Max. Wavelength ~625nm): Chlorophyll a absorbs red wavelengths at a maximum of ~662nm with a small shoulder at ~617nm. Chlorophyll c² has a small absorption peak at ~630nm.
Deep Red (Max. Wavelength ~660nm): Chlorophyll a absorbs light at a maximum of ~662nm. For terrestrial and freshwater plant enthusiasts, chlorophyll b absorbs red light at a maximum of ~646nm.
Far Red (Max. Wavelength ~730nm): Under conditions of saturating or super-saturating light intensities, far red light (absorbed mostly by photopigments associated with Photosystem I) will prevent a 'traffic jam' of electrons within Photosystem II. The use of this light by zooxanthellae is speculative on my part, but remains an interesting possibility.
White (Broad Spectrum,400-700nm): LEDs emitting 'white' light are actually blue LEDs coated with a phosphor that absorb blue light and fluoresce it in a broad bandwidth. 'White' LEDs are quite popular in luminaires built for aquaria. I chose these to offset the blueness of the light and to add small amounts of light in the yellow to red portion of the spectrum. Interestingly, the first luminaire I ordered contained green LEDs to excite the zooxanthellae accessory photopigment peridinin. After a discussion with Build My LED co-owner Nick Klase, I was advised to add neutral white LEDs to the blue ones, as these would be a more efficient source of green light (and the spectrum of this fixture is subjectively very pleasing). In the LED industry, the low quantum efficiency of green LEDs is known as the 'Green Gap'. Blue and Red LEDs are very efficient, but scientists have yet to produce green LEDs that exhibit similar radiometric efficiencies. As a footnote, I tested the cool white LEDs and found them to be 7,123K with a CRI of 87.
Although the two are closely linked, calculating light intensity required for corals or other photosynthetic organisms is much a much less complicated subject than spectral quality. I have written on this subject and reported data obtained by Pulse Amplitude Modulation (PAM) fluorometry. Generally, most corals will do quite well when maintained light fields of intensities ranging from 100 to 500 µmol·m²·sec (~5,000 to 25,000 lux). Tridacna clams (with their thick mantles and self-shading of zooxanthellae) are generally tolerant of more light.
Figure 3 demonstrates the light intensity of a 48" custom luminaire from Build My LED containing LEDs generating light at 450nm, 470nm and 4500K neutral white.
The 60 degree beam angle on my fixture was able to produce PAR values in excess of 550 µmol·m²·sec, which is a very high number considering the fixture only consumes approximately 75 electrical watts. If you need even more PAR, the intensity maps on the company's website claim the 30 degree beam angle can deliver over 1,300 µmol·m²·sec at the same mounting height across the length of the fixture.
In addition to high light levels, Build My LED has been able to solve two of the issues prevalent with LED fixtures in the aquarium industry. Looking at Figure 3, you will not see any lateral hotspots in the intensity map. Build My LED fixtures produce very uniform light across the entire aquarium, which is in contrast to the hotspots associated with the LED 'cluster' design currently utilized by many fixture manufacturers. The cluster design is used to avoid color separation in the aquarium (which is often referred to as the disco effect), but Build My LED utilizes a proprietary optical system design that eliminates the disco effect in the aquarium.
See Figures 4 and 5 for information on light intensities at various depths in an aquarium.
If you want to adjust your light levels, Build My LED fixtures are dimmable with 0-10V controllers. The company offers a manual dimmer for $39.99, and the fixtures can also be dimmed with many of the control systems in the aquarium market.
Heat is an enemy of LEDs. Light output decreases with increasing temperature (the same can be said for fluorescent lamps), so care must be taken in order to maintain a proper temperature range. Build My LEDs has taken an approach that does not utilize cooling fans but instead relies upon dissipation of heat through a heat sink. This sink, an array of cooling fins, does a good job of getting heat away from the luminaire.
I was interested in examining how well this heat sink worked and conducted a simple experiment. The luminaire was plugged in and its temperature was monitored with an infrared non-contact thermometer every five minutes. A small fan was aimed at the fixture when temperature had reached its maximum (96F in an air-conditioned room).
See Figures 6 and 7.
I also checked the temperature of the driver during this procedure and found it to be about the same as the luminaire.
The luminaire is constructed of aluminum with plastic end caps. Ingress Protection Code (sometimes called the International Protection Code) is a system to describe an electrical component housing's ability to exclude dust and moisture. It consists of two digits - the first is for dust (scale of 0 - 6), and the second is for moisture (scale of 0 - 8). The rating for the luminaire itself is IP66, meaning the enclosure is dust tight and allows no ingress. In addition, the moisture resistance rating of '6' means the enclosure allows no ingress of water when water is sprayed from a water jet of 12.5mm (or ½") diameter from any direction at a pressure of 100 kPa (14.5 psi) and a flow rate of 100 liters (26 gallons) per minute at a distance of 3 meters (10 feet) for at least 3 minutes without harmful effect. IP66 is equivalent, in respect to dust and water ingress, to a NEMA (National Electrical Manufacturers' Association) 4 or 4X enclosure. A rating of IP66 does not mean protection against immersion or mean 'waterproof'. The driver/ ballast carries a rating of IP67, meaning it can be immersed in water of up to 1 meter (~3 feet) deep for a short period of time without harmful effects.
I don't mean to suggest that reasonable care shouldn't be exercised in order to avoid water ingress into any electrical device, but it is nice to know that these fixture and driver are built to tight standards.
It is often advertised that LEDs have a useful life of 50,000 hours and it would be easy for a hobbyist to expect a light fixture to last something on the order of 10 years. Unfortunately, this has not been the case with many LED fixtures. Too often, cooling fans fail or the power supply dies. In a day where many LED fixtures are being offered with more and more frills, Build My LED offers no-nonsense lighting at reasonable prices. The design and engineering allows the fixture to remainrelatively cool. The electronic driver is waterproof (meaning no switches). No display of time or built-in timer is incorporated. While some may see these as disadvantages, I personally see them as strengths. It has long been my contention that the more complicated device is, the more likely it is to break. My luminaire boneyard contains more than few LED luminaires which finally failed when a cooling fan broke (often blowing humid, salt-laden air across sensitive internal electronics), or when a driver died (sometimes permanently wired into the fixture). I would much rather supply my own separate fan to cool a luminaire (if needed) than to have to disassemble a fixture and wire in a new computer-type fan, and use an inexpensive aftermarket timer. The driver with these units has a heavy-duty connector which allows driver replacement if necessary.
The anodized aluminum finish is attractive and more resistant to the effects of salt spray than some of the luminaires in painted iron boxes. In short, I want a reliable lighting device and Build My LED seems to have hit the right note.
Many hobbyists use an Apogee quantum meter for taking PPFD (or PAR) measurements. Some Apogee quantum meters (Logan, Utah, USA) offer the option of 'sun' and 'electrical' measurements leaving the hobbyists wondering which to choose. After comparing the Apogee's measurements to those obtained by a 'lab-grade' quantum meter (Li-Cor Biosciences, Lincoln, Nebraska, USA), I recommend using the 'sun' mode.
At the time of this writing, Build My LED offers three pieces of optional equipment. One is a dimmer switch (capable of dimming LEDs to 10% of total output and available for $39.99; See Figure 8) while another is a kit for hanging the luminaire from the ceiling; $24.95). A recently available option is a kit for attaching the fixture to the aquarium and allowing you to aim it (available for $14.99).
At the time of this writing, a 12" luminaire is priced at $119, a 24" at $179, the 36" at $229, and the 48" at $269 (discounts are available for multiple orders). Online ordering allows selection and submittal of all options - simply click-and-drag the LED options into the luminaire template, and click on other options. There is a tutorial for using the ordering portion of the website, but I found it unnecessary as the site is intuitive.
www.buildmyled.com is one of the most impressive I have seen. Over the years, I have programmed more than a few Excel files for analyzing light and I can appreciate the amount of work this site has in it. For example, a few keystrokes can show you:
All products meet RoHS (Restriction of Hazardous Substances) requirements and are CE (Conformité Européenne) certified for distribution within the European Union.
Build My LED offers a 3 year warranty.
Customer service before and after the sale is an important consideration. Co-owner Nick Klase has taken time from his busy schedule to answer my questions. I am impressed with the depth and breadth of his lighting knowledge. It has been my experience that delivery (from Texas to Hawaii) takes about 7 days (very quick considering the luminaire is custom built).
Spectral characteristics of the LEDs were measured with an Ocean Optics fiber optic spectrometer. Kelvin and Color Rendition Indices (CRIs) were determined through use of Ocean Optics' SpectraSuite software after the spectrometer had been calibrated to a LS-1-Cal 2,800K halogen-tungsten light source. Photosynthetic Photon Flux Density (PPFD, 400-700nm) was measured with a Li-Cor 1400 quantum meter/datalogger equipped with an underwater quantum sensor (calibrated to 'air') , while underwater measurements were taken with an Apogee quantum meter.
It was 2005 when I last wrote an article presenting results of a comparison between Photosynthetically Active Radiation (PAR) meters, and the lamps used during testing were metal halides of various kelvin ratings (see Riddle, 2007). In those days, the use of light-emitting diodes (LEDs) for aquaria was something discussed by only a few. Nowadays, use of metal halide lamps is much less popular and usually seen over larger aquaria or those of die-hard fans, yet, to my knowledge, there have been no updates on the utility of different brand PAR meters and their responses when judging output of LEDs.
This article will compare the responses of three quantum meters when measuring LED light output. Specifically, these are meters manufactured by Apogee Instruments™ (model QMSW-SS; Logan, Utah), Li-Cor Biosciences™ (LI-1400 datalogger and LI-189 sensor; Lincoln, Nebraska) and Spectrum Technologies™ (FieldScout; Plainfield, Illinois).
Li-Cor LI-1400 Quantum Meter and LI-189 Sensor Li-Cor Biosciences (Lincoln, Nebraska, USA) is noted for quality instruments, and their meter/sensor combinations have gained wide acceptance within the scientific community. Quality comes at a price (the referenced combination currently costs more than $3,000). The sensor construction is an intricate one - see Figure 1. In addition, the sensor is relatively large and the cord exits the bottom. These facts restrict its use to larger aquaria.
Apogee Quantum Meter Apogee Instruments (Logan, Utah, USA) manufactures entry-level PAR meters and sensors, and many hobbyists have found favor with them due to their affordability. The sensor is relatively small and its cord exits the side making it ideal for use in tight quarters (such as aquaria).
FieldScout Quantum Meter Spectrum Technologies (Plainfield, Illinois, USA) manufacturers a number of products aimed at the agricultural/horticultural markets. Although the meter tested here is the FieldScout Light Meter, the sensors are interchangeable with other Spectrum products (such as their wonderful WatchDog datalogger). The sensor tested here was custom-built for my lab for use when testing artificial light sources. Spectrum does not recommend their quantum sensor for use with LEDs but I wondered just how much of an error there actually is, hence I have included it in this review.
In all fairness, we're comparing an expensive instrument (the Li-Cor setup costing over $3,000) to relatively inexpensive ($300-$400 or so) units. A calibrated light source would be needed to accurately judge the responses of all three meters. This luxury was not available for this review, hence the Li-Cor meter - based on the advertised responses of all three meters - will be considered 'correct'.
There are several things that can affect a quantum meter's reading, these include:
These terms will be used throughout this article:
Glossary Actinity Error: A perfect PAR sensor would be equally responsive to all wavelengths of light between 400nm and 700nm. In practice, this is not possible and response difference between a real sensor and a theoretical one is called the actinity error. Various sensors over- or under-report blue wavelengths while red wavelengths are often under-reported.
Correlated Color Temperature (CCT): is a specification of the color appearance of the light emitted by a lamp relating its color to the color of light from a reference source (a blackbody) when heated to a particular temperature, measured in degrees Kelvin (K). The CCT rating for a lamp is a general "warmth" or "coolness" measure of its appearance. However, opposite to the temperature scale, lamps with a CCT rating below 3,200 K are usually considered "warm" sources, while those with a CCT above 4,000 K are usually considered "cool" in appearance.
Cosine Correction: A light sensor should be able to accurately measure light at angles to ~90 of normal incidence (0), and a cosine-corrector allows this. Two cosine-correction types exist - one type is a hemispherical plastic diffuser dome (used by Apogee and Spectrum Technologies), while the other is a plastic cylinder (that should rise slightly above its housing in order to properly collect light, which the Li-Cor sensor does).
All sensors are advertised to be cosine-corrected, meaning their response will be the same to a beam of light, regardless of that beam's angle of incidence to the sensor (up to a point. Li-Cor advertises their sensor to be correct for light falling at an 80 angle from normal while Apogee states their sensor is ±1% at a 45 angle (from zenith) and ±5% at a 75 degree angle from zenith).
Full Width Half Maximum (FWHM): This is an important concept in light measurement. It is simple and easily defined. While the spectral width of the light source could extend for some distance, the maximum is easily determined as is the half-maximum. FWHM is generally used to define peaks and half-maxima of relatively narrow bandwidths (such as LEDs and other 'specialty' cases such as fluorescence). See Figure 2.
FWHM is not used for broadband light sources (such as sunlight and most artificial light sources). Let's take an example of why FWHM is important. See Figure 14 - it is the spectral characteristics of a combination of blue and white LEDs. This example would share the FWHM characteristics of a blue LED while ignoring the full spectrum characteristics.
Immersion Effect: Reflection of light within a sensor immersed in water is less (relative to a measurement made in air) and results in a greater loss of light. This is due to the refractive indices of plastic and air or water. Hence, more expensive devices (such as the Li-Cor) allow for an 'air' or 'water' calibration to overcome the immersion effect. The Apogee and Spectrum Technologies meters do not offer this option.
Integrating Sphere: A device used in measuring light and especially useful when determining flux or spectra of LEDs. Basically, it is a hollow sphere with a diffusive interior coating. Two ports (one for the LED and the other for a light sensor) are at a 90 angle to one another.
Lambertian Reflectance: Diffuse reflectance is that which appears to be of the same brightness regardless of the observer's viewing angle. Labsphere's Spectralon (a fluoropolymer) offers an almost ideal Lambertian surface. Barium sulfate is a less expensive - but less Lambertian - material.
Light-emitting Diode (LED): A light emitting device consisting of a positive/negative junction where a small amount of electrical current excites metallic compounds doped on a small 'cup'.
Photosynthetically Active Radiation (PAR): Light energy powers photosynthesis. This light's bandwidth has been standardized to that electromagnetic energy between 400 and 700nm (violet to red) per area unit (often 1 square meter) per time unit (usually 1 second). PAR is reported as Photosynthetic Photon Flux Density (PPFD) in units of micromole photons per square meter per second (µmol·m²·sec).
Reflectance: The ratio of the total amount of radiation, as of light, reflected by a surface to the total amount of radiation incident on the surface.
Two pi Sensor; Four pi Sensor: Sensors that collect light only from the direction the sensor is pointed is called 2 pi. A scalar sensor collects light from all directions. A 4 pi scalar sensor resembles an incandescent light bulb. See Figure 3.
Understanding the spectral sensitivities of different PAR sensors is helpful in understanding how accurate measurements will be, especially when dealing with narrow bandwidth light sources, such as LEDs. For our purposes, there are two types of sensors - silicon and gallium arsenide phosphide (GaAsP). The Li-Cor sensor is the silicon type, while the Apogee and FieldScout sensors appear to be made of gallium arsenide phosphide. Figure 4 shows the spectral sensitivity of the Apogee meter, Figure 5 the FieldScout's, and Figure 6 that of the Li-Cor. Unfortunately, Spectrum Technologies does not provide the relative ideal response of their sensor and we therefore must make some assumptions about the actinity errors. Figure 7 is a side-by-side comparison of the Apogee and Li-Cor responses.
The Apogee meter apparently uses a gallium arsenide phosphide (GaAsP) based sensor with a lens/filter in order to slightly correct the sensor's response. However, it is generally agreed that this type of sensor underestimates violet/blue light (400-500nm) and red wavelengths above 650nm.
Apogee's calibrates their quantum sensors at 68F (20C). It reads 0.6 percent high at 50F (10C) and 0.8 percent low at 86F (30C) - see Figure 8. Li-Cor states a change of ± 0.15% per °C (maximum).
When making sunlight measurements, the amount of water vapor (humidity) in the atmosphere can cause lower than expected readings. See here for details:
Note that all reported measurements were made in the air and the impact of the ultimate humidity - water - will impact meters' responses.
In the models tested here, Apogee and Spectrum meters offer two measurement modes to overcome deficiencies in the spectral responses of their sensors. Testing revealed that, on average, there is a difference of about 10% between the two modes. However, spectral quality decides which mode is best for a given light source.
Our testing begins with:
Figures 9 and 10 show the meters' responses to broadband light energy (sunlight, during an overcast morning) and the spectral quality of that light, respectively. As we can see, all meters do a reasonable job of reporting PPFD.
As we have seen, each of the PAR meters have done a reasonable job of reporting PAR values of sunlight, even though their sensors' spectral sensitivities vary dramatically. Results of LED testing will now be presented.
Blue LEDs are ubiquitous in lighting designed for reef aquaria and are often combined with LEDs emitting 'white' light ('white' LEDs are blue LEDs to which a phosphor has been added. This phosphor absorbs some of the blue light and fluoresces it in a broad spectrum). Two blue LEDs were examined. See Figures 11 and 12 (notice the differences in the FWHM of the two).
The following Figure (13) shows the PAR measurements of the Acan blue LED.
This combination of LEDs is perhaps the most popular among reef hobbyists, although the ratio of white to blue varies. Figure 14 shows the spectral characteristics of Acan Lighting's LED luminaire (ratio of 2 cool white to 1 'royal' blue).
When comparing the spectra of blue and white LEDs, it is easy to see the effects of the phosphors added to a blue LED (these phosphors are the same as those used in broad spectrum fluorescent lamps). White LEDs are often used in combination with 'pure' blue LEDs to mimic the blueness of deeper oceanic waters. See Figure 16.
Those manufacturers specializing in reef aquaria lighting have recently begun adding variously colored LEDs to their luminaires (interestingly, the first commercially successful LED luminaire, made by PFO Lighting) used green LEDs in addition to blue and white ones). Use of cyan LEDs has a basis when we examined zooxanthellae photo-pigments. Chlorophyll a is sometimes bound with another photo-pigment - peridinin. This complex absorbs light into the green portion of the spectrum and makes it available for photosynthesis. See Figures 18 and 19 for a spectral characteristics and PAR measurements of a cyan LED, respectively.
Many of the comments made about the cyan LEDs would apply to the green LED examined here. The chlorophyll a/peridinin complex can absorb the light emitted by this LED. See Figures 20 and 21.
Yellow light is only weakly absorbed by zooxanthellae photo-pigments; however, there is some evidence that yellow light plays a part in intensifying the apparent fluorescence of some orange/red coral pigments. See Figures 22 and 23 for results of testing.
Of all the LEDs examined here, those emitting red light are the most controversial. Very little red light is found at depth on natural reefs and it would seem that use of white LEDs (emitting some red light) would satisfy the visual requirements of the hobbyist while supplying more than enough red for photosynthesis. See Riddle, 2003 for effects of too much red light. I'm presently working on the assumption that if a lot of red light is harmful to zooxanthellae, then a lesser amount is proportionally harmful. I am just beginning a project to investigate red light's impact. This will be a part of my presentation at the 2103 MACNA in Florida (www.masna.org).
See Figures 24 and 25.
This completes our observations and analyses of PAR meters and LEDs. Now for our conclusions.
I decided to write this article after hearing anecdotal comments such as 'PAR meters are useless for measuring LED output' and 'Corals don't survive long-term under LEDs'. The latter has not been my experience, but I really had no idea about the former statement. The concept for this article seemed valid enough and I suspected the article could be written in short order. I had the meters and the LEDs and making the measurements could be made quickly - or so I thought. After writing almost 300 articles for hobbyist-related publications over the course of over 25 years, one might think I would have a good handle on the complexity of a project. In this case, I thought I could research and write the article in 2 or 3 weeks. As it turned out, this work required months of research, construction, measurement, and analyses. The results are complex. To reiterate, we're comparing two relatively inexpensive meters against one costing roughly 10x as much. When measuring sunlight, the Apogee and Spectrum Technologies meters report PAR values that compare favorably to those of the Li-Cor. Additionally, Spectrum Technologies states on their website that their sensor is not useful in making measurements of LEDs (a bit of an overstatement as we shall see).
This product evaluation took on added complexity when we consider two of the meters offer two measurement modes - in essence, we are comparing 5 meters, not three. The Apogee and Field Scout meters offer the option of two measuring modes ('Sun' and 'Electric'). This is done in order to offset limitations of the spectral sensitivity of their sensors. The more expensive Li-Cor sensor and meter has no reason to offer this option due to the superior spectral response.
Interestingly, the difference in 'Sun' and 'Electric' measurement modes is almost always about 10% (suggesting the difference is simply the result of a preset electronic correction). However, this correction cannot overcome the ability of the sensor to 'see' light. Therefore, Table 1 is offered for those wanting to measure narrow bandwidth light sources such as LEDs.
|Field Scout
|Blue (450nm)
|X (Low)
|Blue/White Combo
|X (Low)
|X (High)
|White (7,300 K)
|X (High)
|Cyan (505nm)
|X (High)
|X (High)
|Green (517nm)
|X (High)
|X (High)
|Yellow (595nm)
|X (Low)
|X (High)
|Red (647nm)
|X (Low)
|X (High)
|Sunlight (Mostly Sunny)*
|X (High)
|X (High)
|*Sky Conditions and Sensor Response: As even the most casual observer knows, sky conditions can drastically alter its apparent color composition. The most obvious examples are the yellow 'morning' and orange 'sunset' colors. However, more subtle effects are in play during the day. 'Cloudy' refers to the blue sky and sun being hidden completely by opaque clouds. 'Sunny' conditions exist when no clouds are present. A 'mostly sunny' sky is obscured by no more than 2/8ths opaque clouds. 'Partly sunny' and 'mostly cloudy' means 3/8 to 5/8ths and 6/8 to 7/8ths opaque clouds, respectively. The term 'clear' (as opposed to sunny, naturally enough) is used for nighttime observations. 'Fair' is not a useful meteorological term and should be avoided.
1 The impact of volcanic smoke (vog) on the meters' performance is unknown. Although the measurements were made when conditions were considered to be 'mostly sunny', there is a certain haziness to the sky. Vog is known to absorb some ultraviolet radiation. In addition, there is a considerable amount of seawater aerosols in the air.
Simply using the manufacturer's sensor spectra response chart can lead to incorrect conclusions. There were some surprises. It seems to be current wisdom that the Apogee meter under-reports blue light, yet the results of testing showed the meter performed well when in 'sun' measurement mode (while the electric mode read low). Similarly, the Apogee did very well in 'sun' mode when analyzing the output of 7,300 K white LEDs. In addition, the Apogee and FieldScout meters repeatedly performed best when measuring sunlight when in the 'electric' setting.
Based on these observations, inexpensive PAR meter have some utility for measuring light produced by LEDs.
If you have a lux meter, it is possible to convert lux measurements to PAR values. Use these results with some caution - in most cases it would be safe to assume the results will be low.
Spectral analyses were performed by Ocean Optics USB2000™ fiber optic spectrometer and SpectraSuite™ software (Ocean Optics, Dunedin, Florida). It took some doing to design and build a workable integrating sphere from scratch (on the order of weeks). Original prototypes were made of papier mâché and were large (6-inch, or ~150mm) diameter, then reduced to 3-inch (76mm). These proved to be too large and did not sufficiently concentrate light. Ultimately, ping pong (table tennis) balls were used. Their exterior were painted white and the interior of the hollow spheres were painted matte white and then coated with barium sulfate (ACS grade) in order to create a surface with good diffuse spectral reflectance characteristics. Barium sulfate was mixed with un-tinted white latex paint (90:10 weight: weight). Two 1/2" (12mm) holes were drilled into the sphere at a 90 angle. An interior baffle was placed adjacent to the sensor port to prevent light from falling directly upon it.
Barium sulfate is known to offer good reflectance at ~425 - 700nm. To check this, the barium coating was compared to a diffuse reflectance standard (Labsphere Spectralon WS-1-SL, a fluoropolymer offering a highly Lambertian surface with reflectivity of 99% at 400-1,500nm). See Figure 26 for the reflectance of the barium sulfate coating.
Figure 27 shows the integrating sphere.
The integrating sphere would not collect enough light in some cases. To overcome this problem, measurements were made of the high intensity output of a LED luminaire manufactured for aquarium use (Acan Lighting, model 600-18B, Commack, NY). See Figure 28.
Determination of Correlated Color Temperature (CCT) was determined with an Ocean Optics USB 2000 spectrometer and SpectraSuite software. In order to do so, the spectrometer's measurements must be calibrated to a known source. To this end, an Ocean Optics' LS-1-Cal tungsten halogen NIST-traceable light source was used. This light source had little use on it and total hours fell well below the cutoff of 50 hours (when re-calibration is required). Settings of the software included a setting for 'emissive' color (that emitted by a light source such as a LED) and 2 Observer (photopic, daylight observer).
Lux measurements were made using a Gossen Luna Pro lux meter (Gossen Foto-und Lichtmesstechnik GmbH, Nürnberg, Germany).
Apogee recommends calibration of their meters ever 3 years, while Li-Cor recommends every 2 years. The Apogee meter has not been calibrated since purchase. The Li-Cor LI-1400 data logger is new and its sensor was rebuilt about 5 years ago.
To check if your PAR meter needs re-calibration, see this site:
Note: This calculator works if the sky is truly clear. It did not perform well here in Hawaii due to the amount of 'vog' from the continuing volcanic eruption.
On September 1, 2011, Ecotech Marine introduced the Radion XR30w. The highly anticipated LED light was marketed as a "purpose-built" modular, upgradeable lighting system. Ecotech Marine's President Tim Marks remarked at the time: "Our goal was to deliver a product with the ability to evolve and get better over time, not become obsolete."
Flash forward a year: On September 15, 2012, Ecotech Marine made good on the Radion's upgrade potential when they announced the Radion XR30w Pro. The Pro is an evolution of the original XR30w and builds on its strengths with additional features and increased output. As such, my review will focus on the improvements the Pro brings to the table when compared to the original, well-known, and highly-regarded Radion.
• White: 8 Cree XT-E Cool White (5w each)
• Red: 4 Osram Oslon SSL Hyper Red, 660nm (3w each)
• Yellow: 2 Osram Oslon SSL Yellow, 590nm (3w each)
• Green: 4 Cree XP-E Green, 520nm (3w each)
• Blue: 8 Cree XP-E Blue, 468nm (3w each)
• Royal Blue: 8 Cree XT-E Royal Blue, 442nm (5w each)
• Indigo: 4 SemiLEDs UV, 415nm (2.5w each)
• "Ultraviolet": 4 SemiLEDs UV, 405nm (2.5w each)
*All wavelengths are the peak emitted wavelength of the LED.
Length: 11.8 inches (30 cm)
Width: 7 inches (18 cm)
Thickness: 1.5 inches (3.9 cm)
Max Wattage of Radion Fixture: 170 Watts
Max Wattage of LED Channels: 155 Watts
For more information, visit: www.ecotechmarine.com
The Radion XR30w Pro is an evolutionary product that shares much of the design and components of the original XR30w but with some key changes to enhance its functionality and performance.
A look inside the XR30w Pro. Notice the new black LED circuit boards.
The most obvious and significant improvement over the standard XR30w is the new LED array cluster. The Pro features eight more LEDs over the first generation XR30w and ten more LEDs over the second generation "G2" XR30w. (42, 34, and 32 respectively). Like the recently announced XR30w G2, the Pro now uses the new 5W Cree XT-E white and royal blue LEDs. The XT-Es are more efficient than the XP-E and XP-G bulbs they replace (and is consequently why the XR30w G2 requires two less bulbs than the first generation).
The additional LEDs are comprised of two 3W Osram Oslon SSL Yellow diodes (590nm), four 2.5W SemiLEDs "Indigo" diodes (415nm), and four 2.5W SemiLEDs "UV" diodes (405nm). The 590nm diode - a spectrum bordering between yellow and orange - is centered on each of the LED cluster arrays and was chosen by the Ecotech design team "to provide a more rounded spectrum" according to Tim Marks.
The indigo and "UV" diodes warrant a paragraph of their own because few aquarium LED fixtures include sub-440nm "royal blue" spectra, and those that do often output only token amounts. The Pro, on the other hand, includes a class-leading 20 watts of sub-440nm light. Ecotech Marine recognized that lower wavelength bulbs are less efficient so the Radion would require a substantial number of sub-440nm LEDs to produce meaningful light in this spectral range. Thus, Ecotech Marine engineers added eight 2.5W LEDs to provide the bottom end of the spectrum.
The four 415nm "indigo" LEDs are a close approximation to the tried-and-true 420nm actinic fluorescent lights reefkeepers have used for decades. The 405nm LEDs are technically not UV (UV is defined as spectra between 10-400nm) but extremely close. The four 405nm LEDs extend the Pro's combined spectrum to encompass nearly the entire 400-700nm photosynthetically active radiation (PAR) range
Below are two photos comparing the first generation XR30w (left; upgraded with the TIR lens) and the new Pro model (right; TIR lens are now standard on all Radion models). (Read our review on the TIR lens)
Beyond the new yellow, indigo, and "UV" LEDs, you will also note the new white XT-Es produce a warmer colored white light compared to the previous white XP-Gs. Both LEDs are marketed by Cree as ""cool white," yet they look visibly different. You can also easily spot the design difference between the older royal blue XP-Es and the new XT-Es.
The Pro also employs a redesigned "water-resistant" fan, which operates at approximately the same volume as the original Radion. The top acrylic panel (including the touch controls and mounting points) remain exactly the same as the standard XR30w.
I will not review the Pro's user interface simply because it is the same interface as the original Radion. Anyone who has used a Radion will know how to use the Pro, and there is an abundance of reviews/documentation about the Radion user interface posted over the past 15 months. The one notable change to mention is the Pro includes one additional control channel (six channels vs five channels on the standard XR30w G1 and G2) to control the sub-440nm LEDs.
At the time of this writing, Ecotech Marine is still beta testing their new EcoSmart Live web-based interface, which will of course be able to control the Radion Pro. Note: The beta platform is now open to the public so all Radion Pro owners can use the beta EcoSmart Live if they so choose to.
Dr. Sanjay Joshi plans to test the Ecotech Marine Radion XR30w Pro for an upcoming Advanced Aquarist magazine article. His tests will provide definitive empirical data on spectrum and light distribution. I will do my best to describe the Pro's light within the scope of this review.
So the big question is: Just how much more light do the new LEDs add to the Pro? The answer is: Quite a lot.
Using our Apogee Quantum Meter, I measured the the PPFD 36 inches directly under the center (in between the pair of LED clusters) of each Radion fixture.
These results tell us the Pro is significantly brighter than the original Radion (even with the TIR lens upgrade):
(Note: These measurements are for comparative purposes only)
Advanced Aquarist does not currently have access to the Radion XR30w G2. However, turning off the sub-440nm channel on the Pro should adequately replicate the G2. With the "UV" and "indigo" LEDs switched to 0%, the PPFD was reduced to 127 μmol m-2s-1, which means the Pro produces approximately 11% more PAR (requiring 15% more power) versus the G2.But quantity is only half the story of the Pro. What about its light quality?
The Pro produces a richer light than the original XR30w. Ecotech does not assign correlated color temperatures (AKA Kelvin rating) to their LED lights because it's an inexact math at best. To the naked eye, the Pro produces a warmer and more natural color rendition than the first generation Radions. While I would describe the original Radions as a cool blue-grey light at full output, the Pro hedges towards a warmer purple-white. We can safely assume the difference is accounted for by the new yellow and indigo LEDs as well as the warmer XT-E white LEDs. And sure enough, when you dial the "UV" channel to 0%, the Pro produces a more cool, grey tone. The sub-440nm do not contribute much in the way of perceived brightness, but they definitely add a richness to the light that is hard to describe.
It is also worth noting that certain corals fluorescence more under the Pro than the first generation Radion (or metal halides for that matter). This is one unmistakeable benefit where the 400-440nm spectra LEDs can really enhance the appearance of the livestock. Reefkeepers already know that "true actinic" lighting can bring out biofluorescence that higher spectrum lighting can not, so it's not surprising that the addition of the Indigo and "UV" LEDs help flesh out corals' colors. And the Pro accomplishes this feat without making the entire aquarium look unnaturally monochromatic blue.
All in all, the Radion XR30w Pro is a true "full-bodied" high intensity light source for the tropical marine environment. Furthermore, at full output, the Pro produces a pleasing and balanced color unlike some other >150W multi-color LEDs on the market.
The XR30w Pro consumed 171 watts at full power (virtually spot on to the advertised 170W rating) and 8.9 watts when all the LEDs were manually turned off but with the fan running. When the LED light was disconnected from its power supply, the power supply still drew 5.2 watts.
Note: The Pro shares the same power supply model as the original and G2 Radion.
The Ecotech Marine XR30w Pro does everything I expect of an advanced LED lighting system. It is a highly flexible and controllable lighting fixture which provides ample amounts of PAR with "natural" color rendition. The Pro builds on the strengths of the original Radion; It does not reinvent the wheel but rather improves upon a lighting fixture that has been vetted by thousands of satisfied Radion users. And this "modular evolution" concept is exactly how the Radion platform was conceived.
I will conclude my review on a personal note: I found previous LED lights (including the first generation Radions) lacked the power or color rendition to replace my trusty 250W metal halide and lumenarc III reflector system used over my 176 gallon reef. The Ecotech Marine XR30w Pro is the first LED unit to impress me enough with both its light quantity and quality that this reviewer has finally decided to make the switch from MH to LED.
FCC Disclosure: This product was provided by the manufacturer for the purpose of review.
New LED fixtures continue to be introduced into the hobby. Specifically, there is an increase in the number of LED fixtures providing a more fuller color spectrum with multiple channels of control, allowing the user more freedom in custom tuning the light output. Continuing in the same vein as my previous LED lighting tests, this article presents data on light intensity and spread along with spectral plots for several new LED fixtures. Table 1 presents a list of the LED lighting fixtures reviewed in this article. Each of these was tested using the same set up as my previous reflector tests, using a 3'X3' grid with a spacing of 3" in the X,Y direction. The fixtures were centered on this grid, and PAR was measured as PPFD (Photosynthetic Photon Flux Density) in micromoles/m2/sec using a LICOR 1000 data logger and a LI-192SA underwater cosine corrected sensor calibrated for both air and water. The data logger was set to average 5 readings for each data collection point. The data was imported into Microsoft Excel for analysis and the data was plotted to display the light spread and intensity at various distances. 4 plots of the data with 2 plots at each distance were generated showing:
The spectral distributions were measured using the Licor LI-1800 spectroradiometer. The spectral data was collected from the various LEDs and normalized such that integrated light output (spectral irradiance) between the wavelengths of 400-700 nm was 100 Watts/m2. Data was collected at full power output for the individual channels of light control (eg. Blue, white) along with data with ALL LEDs on at full power. The data was normalized so that the full output was at 100 Watts/m2 over the wavelength range 400-700 nm. The various LED color outputs were then scaled by the same scale factor to allow of determination of the contribution of the various LEDs to the full output. The results are plotted as a Spectral power distribution plot.
LED Fixture
|AquaIllumination: AI-Vega
The fixtures were tested for light spread and intensity at 24"and 30", unless otherwise noted. Power draw was measured with a Kill-A-Watt meter.
The Mazarra P series is a modular lighting system that is sold as a complete unit with LED modules, frame mounts, power supply, and controller. The modular design allows for the addition of additional LED modules, on a support frame that is adjustable to fit a wide range of aquarium sizes. The mounting of the LED modules allows for sliding the location of the LED modules as well as allowing the LED modules to be mounted at an angle. The ability to adjust angular orientation allows for better control in directing the light output. It addition to the flexibility in mounting, this lighting fixture also allows for a plug and play replacement of the LED bulbs and the optics. 100, 70 and 40 degree optics come standard with the modules. The controller provides 4 dimmable channels, and each controller can control 16 LED modules. The LEDs used in each module are Cree XLamp XM-L, Philips Luxeon Rebel, Epileds Dual-Core, and Cree XLamp RP-G LED chips. As per the specification, each LED module is rated as 60W (4-Cree XLamp XM-L 7000-8000K @ 1500mA, 4-Philips Luxeon Rebel 460-490nm @ 1000mA, 4-Philips Luxeon Rebel 440-460nm @ 1000mA, 1-Epileds Dual-Core 400-410nm @ 1000mA, 1-Epileds Dual-Core 410-420nm @ 1000mA, and 2-Cree XLamp XP-G 3000K @ 1000mA).
The AI-Vega is the next generation LED light fixtures from Aqua Illumination. Compared to their previous products, popular AI-Sol and Sol-Blue, the AI Vega offers additional LED colors and 6 channels of control. Each LED fixture comprises the following LEDs:
A wireless controller allows for infinite control of the 6 lighting channels to create a wide range of color combinations, along with programing in special effects such as clouds and lightning.
As LED lighting moves further into the mainstream, there is new effort being made to provide a fuller spectrum light that can be tuned by the aquarist to satisfy both the demands of the corals as well as the visual pleasure of the aquarist. Hopefully this data will help the aquarist make an informed choice on what to expect from the individual LED fixtures and how best to utilize them to achieve the desired coverage and light intensity.