Quote Originally Posted by beachvibesbyeff
I have a fish thermometer on the inside...we'll it's a suction and after like 2 days it falls off and I have to replace it...it's always around 80...and no I do not have a therm/rheo...I know if anything I need to increase the humidity but that couldn't be why my snake has this on her belly...
You need to have something sitting on the bottom of the tank to measure the heat being put out by the UTH. They can get hot enough to burn snakes, so you also need a thermostat to control that output.

Personally, I use Acurite thermometer/hygrometers from Walmart. They cost around $12 and have a probe that can be placed over the UTH. You can get a dimmer switch to control the UTH until you can afford a good thermostat, if needed.