Metal Halide Aquarium Light
A metal halide aquarium light is believed by many reef tankers owners to be the best choice for lighting the aquarium.
Metal halide is a high intensity discharge light. HID lights are valued for their high output and their compact size. Because of the compact size and high energy output these types of lights are used in many commercial and household applications. They are used as growing lamps for plants and are excellent security lighting. They are also used to light sports stadiums because of the exceptional high input of white light. Metal Halide lighting also is a heat source.
A metal halide aquarium light, accomplishes a couple of things very effectively. First obviously it supplies light, but for reef aquariums it adds more than just light because the light is so intense they produce a "glitter effect" which most divers are familiar with. The glitter effect is produced in natural reef areas when the surface water acts as a lens and concentrates a point of light. This same effect comes from using a metal halide aquarium light. Fluorescent lighting is more diffused and does not produce the same effect. A metal halide aquarium light also can light deeper areas in the tank. Reef tanks require lighting to all the areas and usually are at least 16 inches deep, a metal halide aquarium light will reach at least that depth and beyond, insuring all of the organisms have the light they need. A metal halide aquarium light may not be the best choice for smaller reef tanks unless there is a pendulum light over the tank so that the light itself is not to close to the tank. Metal halide aquarium light throws out at least 150w of power which is more than a small tank can handle. A fish only tank can use any kind of lighting but a reef tank really will benefit from a metal halide aquarium light.
A metal halide aquarium light should always have a cooling fan installed in the casing of the light. They can get very hot and can explode if they overheat. The water temperature should also be monitored to make sure the metal halide aquarium light is not heating things up too much.
In an air conditioned home with the right size reef tank a metal halide aquarium light will keep the tank lit beautifully.