This is the only one I could find in my town, and the store only had the one. I have a 50 gallon tank, 16 inches high, with a screen top. This is the only light I will be using, but I'm not sure if it is too powerful for the enclosure. I have it about two inches above the screen. So the light is about 20 inches up from the bottom of the tank. Is this going to be a problem?