Aquarium lighting describes any type of artificial lighting that is used to illuminate an aquarium. Some types of aquaria such as reef aquariums and planted aquariums require specialized high intensity lighting to support photosynthetic life within the tank. Freshwater Freshwater aquarium lighting is commonly provided by screw-in incandescent bulbs, fluorescent tubes and LED lamps. Incandescent lighting is becoming less popular because it uses much more energy and produces more heat than the other lighting types. Compact fluorescent lighting with a compatible screw-in base is frequently used as a direct replacement for incandescent bulbs. Freshwater planted aquariums require more specialized light sources. High-intensity compact fluorescent bulbs, high output fluorescent bulbs or metal halide lamps are often used over such aquariums to encourage plant growth. In addition to providing a much stronger light source, these light sources also offer a better spectrum for plant and algae growth than standard lighting. However, this metal halide lighting often uses more electricity and can produce excessive heat. Other newer sources for planted aquariums that use less electricity and produce less heat include the T2, T5, SHO, and LED. The LED aquarium light fixtures generally are the most efficient, although the T2, T5, and in particular the SHO, have their positive planted aquarium applications as well. Brackish Brackish aquarium lighting is similar to freshwater and planted tank lighting, depending on the species included. Brackish aquariums may also include infrared or UVB bulbs (or both types) for basking animals such as turtles. Marine Fish only In fish-only marine aquariums, lighting is intended only for illumination. Lighting is chosen primarily with aesthetic considerations for optimal viewing of the fish. The lighting is generally of much lower intensity than is used in reef aquariums to limit algae growth. Reef The lighting used for reef aquariums is the highest intensity of all aquarium types. Typical light sources types include LED, fluorescent, metal halide, and sometimes plasma lamps. Simple lighting setups use a single lamp or multiple lamps of a single type. More advanced setups can include several lamp types and can also include lamps of different colours. Lamp colour plays an important role in reef aquarium lighting for both aesthetic preference and to optimally sustain the photosynthetic life within the aquarium. Many corals require a deep blue or actinic spectrum of light to thrive. T5 High Output fluorescent bulbs which are thinner than traditional T8 bulbs and provide a much