I decided to wait some time before posting to see how things went with this product. I first cleaned then installed the Marineland Emperor Bio-Wheel 400 Power Filter, much the same as any other filter would be installed. I can say I have some experience even with filters exactly the same as the Marineland Emperor Bio-Wheel filter, as I own a 10-gal aquarium with a Marineland Penguin filter, and this was to replace an old (7 yr old) Penguin 330.

The filter is NOISY. Freakishly noisy; like something that filters a 5000 gallon aquarium noisy. I wish I could say it was just a lone bad unit, but after ordering the unit, I researched a little to find these things have a tendency to be noisy. Seriously, do yourself a favor, and google "noisy emperor 400", see the hundreds of other complaints? Yes, some may get good units, but there's a good chance you won't. I even let the thing run for several days before judging, since others said it may need to "break in" (which, yes the one on my 10 gal did get quieter, and now is whisper quiet). After 3 days, I contacted Marineland, which, while not the friendliest of folks, were fairly helpful. The first time around, they sent a new impeller, even though I had thoroughly inspected the impeller and found no mechanical flaws, I figured couldn't hurt to try. New one arrived, didn't help any. Let it run for a few days, no improvement. Then, I contacted them again, they sent an entire new filter! Pretty good service I have to say, but sadly, the new one suffers the same obnoxious "garbage disposal"-like sound. Yes, I've messed with a billion different ways to seat the impeller, and well quite frankly, if someone who's worked with dozens of filters in the past can't properly seat the impeller, it really isn't consumer-ready.

Beyond that, the filter has a ton of great features. The spray-bars that keep the bio-wheel's wet and spinning work great. The filter has tons of room for flow, plus a total of 4 slots for filter media, and includes two easy-to-fill filter cartridges. The flow-rate is good. It really would be an excellent, solid product if it weren't made with cheap materials, and weren't the noisiest filter I've ever owned. The other negative is the bio-wheel filters really create a lot of choppy surface water, so feeding fish is messy, and I recommend getting some sort of floating-feeding device.

It's past the return period, which Marineland was perhaps counting on, so now I"m stuck with it. I'll try contacting them again and see what happens, and will post if anything different comes from it. It seems you either love it and get a great unit, or you get a flawed, noisy as all heck filter. The price is excellent, but to be honest, you're better off with a Penguin, which yes while the Emperor's are supposed to be the higher-end product, very few have issues with the Penguin's compared to the Emperor's. Or an Aqua-Clear, but you have to be gentle with them (they have a tendency to crack/break).

***Update 9/12/2011***

Well, after approximately 3-4 months of continuous use, the filter is now significantly quieter then when I received either one of them. Still not "whisper" quiet, but sounds decent enough for a larger filter. I've added a star, since this is a decent product overall, but the fact that it took that many months of having to have my office door completely closed at night just so we don't hear it, I can't give it any higher than that. YMMV.
I decided to wait some time before posting to see how things went with this product. I first cleaned then installed the Marineland Emperor Bio-Wheel 400 Power Filter, much the same as any other filter would be installed. I can say I have some experience even with filters exactly the same as the Marineland Emperor Bio-Wheel filter, as I own a 10-gal aquarium with a Marineland Penguin filter, and this was to replace an old (7 yr old) Penguin 330. The filter is NOISY. Freakishly noisy; like something that filters a 5000 gallon aquarium noisy. I wish I could say it was just a lone bad unit, but after ordering the unit, I researched a little to find these things have a tendency to be noisy. Seriously, do yourself a favor, and google "noisy emperor 400", see the hundreds of other complaints? Yes, some may get good units, but there's a good chance you won't. I even let the thing run for several days before judging, since others said it may need to "break in" (which, yes the one on my 10 gal did get quieter, and now is whisper quiet). After 3 days, I contacted Marineland, which, while not the friendliest of folks, were fairly helpful. The first time around, they sent a new impeller, even though I had thoroughly inspected the impeller and found no mechanical flaws, I figured couldn't hurt to try. New one arrived, didn't help any. Let it run for a few days, no improvement. Then, I contacted them again, they sent an entire new filter! Pretty good service I have to say, but sadly, the new one suffers the same obnoxious "garbage disposal"-like sound. Yes, I've messed with a billion different ways to seat the impeller, and well quite frankly, if someone who's worked with dozens of filters in the past can't properly seat the impeller, it really isn't consumer-ready. Beyond that, the filter has a ton of great features. The spray-bars that keep the bio-wheel's wet and spinning work great. The filter has tons of room for flow, plus a total of 4 slots for filter media, and includes two easy-to-fill filter cartridges. The flow-rate is good. It really would be an excellent, solid product if it weren't made with cheap materials, and weren't the noisiest filter I've ever owned. The other negative is the bio-wheel filters really create a lot of choppy surface water, so feeding fish is messy, and I recommend getting some sort of floating-feeding device. It's past the return period, which Marineland was perhaps counting on, so now I"m stuck with it. I'll try contacting them again and see what happens, and will post if anything different comes from it. It seems you either love it and get a great unit, or you get a flawed, noisy as all heck filter. The price is excellent, but to be honest, you're better off with a Penguin, which yes while the Emperor's are supposed to be the higher-end product, very few have issues with the Penguin's compared to the Emperor's. Or an Aqua-Clear, but you have to be gentle with them (they have a tendency to crack/break). ***Update 9/12/2011***

Well, after approximately 3-4 months of continuous use, the filter is now significantly quieter then when I received either one of them. Still not "whisper" quiet, but sounds decent enough for a larger filter. I've added a star, since this is a decent product overall, but the fact that it took that many months of having to have my office door completely closed at night just so we don't hear it, I can't give it any higher than that. YMMV.