Aquariums that require high output lighting, typically metal halide lighting, pose some problems for aquarists. These lights are very expensive to purchase, create a great deal of heat, and are expensive to operate, and replace. Using a moving light source on your reef or live plant aquarium can help solve some of these problems, you can keep your light closer to the water surface, and maximize the light energy that reaches into the aquarium. Another benefit to using a moving light system is the number of light fixtures needed to cover a given area. A six foot long aquarium can be sufficiently covered by two moving metal halide light fixtures, where it would require at least three were they stationary. Less light fixtures means less heat, less operating cost, and fewer bulbs to replace annually and more natural growth patterns.
Using light rails are not going to be practical for all applications. Smaller tanks are not practical to use these systems on, and you need to have the space to install the equipment. Applications such as “in wall” aquariums that have all the equipment hidden from view, and especially large aquariums or coral propagation systems will be able to take better advantage of what the use of light rails has to offer.
Beyond the cost and functional benefits of a light rail system, they are just plain cool to watch. The moving light source over an aquarium creates an ever changing mix of shadows and colors in your aquarium as the angles of light change on the livestock and objects in the aquarium. A moving light system is definitely a gadget geeks kind of device.