it all depends on how big the tank is i have i 55 gal i use a screen top with aluminum foil i keep my nocturnal heat light in the cage it is 75 watts one side its 95 the other 85. Having a big tank i struggle with humidity the aluminum foil helps as well as misting it every once and a while and the cool side of my tank has condensation on it. i keep my house pretty warm so i have nu use for a uth