thank you all for the helpful tips, however, my thermostat does not read the temperatures, I have a separate digital thermometer/hygrometer that also comes with a probe, and I have it underneath all of the substrate and above the UTH. Also, If the case is that the glass must be around 89-91, than I would not need a CHE, because my ambient temps seem to be fine, theyre in the low 80's, and at the other end of the tank, its about 75 degrees Fahrenheit.