Illuminating your aquarium can get very expensive, especially when it comes to your electric bill. Extra long aquariums require several light sources, which can really drive up costs. To combat this, you could use a light moving rail. Over long aquariums, a single light is mounted to the rail and moves slowly back and forth over the tank. This allows the full tank to be illuminated with fewer light pendants. The rails, when compared to a fully functional set of metal halide pendants and ballasts, are relatively inexpensive and use little energy. Of course, using this light setup means your corals don’t get the same amount light and you are forced to look at a moving light all day long.