I have one on my 10 gallon (20"s long) and I just made some stands with PVC. Just made 4 pieces the same length (or you can also use couplers) and cut a notch in them about halfway so it will fit on the rim of your tank. I painted them black and they sit perfectly between the tank and the light. Can be more of a pain though if you try to put your hands in the tank, cause they can fall. But instead of cutting off one side to fit on the tank, you can make a notch between each side for it to rest on.