Does anyone know what temperature differential setting i should put for my thermostat that will control my under-tank heater? Also what type of tape should I use to tape down the thermostat probe onto the under-tank-heater? And where should i put my thermometer probe/how should i hold it down? Sorry for the nooby questions, i just switched from a ceramic heating bulb to the under-tank heater and i just got the thermostat.