For my Leopard Gecko, I have a 10 gallon glass tank, 60 watt lamp, under tank heater which is already attached to the tank (uth does not have a sensor) , and sand substrate. The problem is that both the lamp and the heater when used separately, each keep the tank warmer than they should. I realize I can get a 40 or 25 watt bulb to solve the day temperature problem, however, my dilemma is that I've been told that the uth should stay on 24/7 to ensure that it doesn't get too cold at night. I've heard of reptile owners buying something that the uth plugs into which has a sensor on it that can be buried in the sand at the warm end of the enclosure. The 3 pet stores in my city sell something similar to this but in all 3 stores, the reptile specialists have discouraged me from buying them and have said either that they don't work in sand, or just don't work very well. The cost has been between $25 & $35 for these products. I don't really want to spend that much and especially not on something that I don't have much confidence in. Does anyone have something to plug a uth into with a temperature sensor to put in the sand that works? If so, please tell me about it, like how much did you spend and where did you get it, etc.? Please help soon.
I use a dimmer switch with mine. Once you find the right temp you just leave it alone. It's manual control, but it works and is cheap.
If you don't want to use the UTH, you could just get a infrared bulb for night. It will produce enough heat but not much light. Plus, you have to remember that it gets cold in the desert at night. you don't have to keep the tank in the 80's all the time. You do want it to cool off at night. I would try using the two lamps, on separate timers, with one on during the day and one on during the night. And the dimmer switch is a great idea, especially for the daytime bulb, if it's too much heat.