Lets see here... I am running with a 55 gallon tank for my little 4 month old snake... and the way I am running...Alos I live in the Bay area CA.. so the ambient temps are more condusive for me.... I have a Large UTH under one side of the tank. I have ti hooked into a dimmer because if I let it igo by itself it hits 110 degrees on the substrate... no extra lights. bells or whistles...