The subject of lighting is quite complex and confusing. There are a number of different options available for lighting and it is not easy to decide which is the most appropriate. While some generalisations can be made, it is helpful to understand The Properties of Light as well as something about the Underwater Lighting Conditions the planned inhabitants will have experienced in the wild.

For a Fish Only tank, the decision is quite easy. Fish require enough light to see and that is all. This can easily be achieved with a few normal output fluorescent tubes. The choice of tubes is fairly arbitrary and you should choose what you find appealing. See: Fluorescent Lamps for a list of inexpensive lamps that can be used.

Most reef tanks are used to house organisms that require light for photosynthesis. (See Photosynthesis for a summary on the subject.) The organisms we are most interested in are animals with photosynthetic symbionts. Generally, the lighting requirements of these animals correlate with the depth from which the animals are normally found. Those found in shallow water, normally require high intensity lighting. Those found in deeper water can make do with much lower intensity of lighting.

When planning the lighting for a new tank, the needs of the organisms with the highest lighting requirements should be considered first. If you can provide for these organisms, it is relatively easy to provide areas of lower intensity through the use of caves, overhangs or the placement of organisms away from the lamps.

Types of lighting

There are basically two types of lighting that are useful for marine tanks: fluorescent and metal halide.

Fluorescent lamps are available in a number of different form factors as well as different output levels.

Last updated: November 10, 2002