A under tank heater is adiquite when the room temp. is high enough to hold the proper humidity in the tank. The humidity is dependent upon the ambient air temperature in the tank. Improper humidity levels have a lot to do with
RI infections. In the case that the tank's air temp is too cool I would suggest putting the light on a reostat as a minimum. The only time you really need a thermostat is when the room temps fluctuate a lot, which most rooms tend to do. Oh, and in my book a digital thermometer is a must, most analog ones I have seen (ESU, Zoo Med, etc.) work ok for awhile and then can be off 4-5 degrees before you know it, sometimes more once they are introduced to a high humidity enviroment.
[addsig]