I brought this up last week and it's about to drive me crazy. I have 3 balls, 3 tanks, 3 Accurite Termometers with probes. One tank is using heat tape with a thermostat, have it set at 92 and on my thermometer is only reading 81 degrees. On the second tank, I have an exo terra heat mat on a dimmer, with a temp of around 84 degrees and the dimmer will not work with it. On the third tank (which is killing me), I have a zoo med with a dimmer as low as it can go with a temp of around 108 degrees. Please tell me why this is. I tried both the zoo med and exo terra with the thermostat and neither one would adjust. Help please.