What are you keeping in the tank? In my gray tree frog tank, I have a 50 watt blue daylight lamp and that is plenty. They are in a 35 gallon hex tank. My toads and spring peepers are both in a 10 gallon tank, a 25 watt lamp seems to work just fine for them. In the winter, if they get too chilled (we live in an old drafty house) I will use an under tank heater on the side. I might hibernate them too...haven't fully decided yet.