I have a glass tank and it gets pretty chilly here in Utah as well. Doesn't help that I like my room nice and cool too. First I lined the whole tank except the front and a spot for the CHE with some foam insulation board from the hardware store. You can get them in 4X2 foot pre-cut sections. Also have a ceramic heat bulb and under tank heater between the bottom of the tank and the foam with a thermostat between the glass and UTH. That was sufficient til the temps plunged what seemed like overnight. I had to add a little 250 watt space heater that I've got sitting about a foot or so away from the tank and now my temps are spot on again. It's a low enough wattage that I was able to run it through a thermostat like my CHE and UTH. It zaps the humidity out pretty quick with all those heat sources so I get to watch it like a hawk til I can get an auto mister. Just make sure ALL heat sources are regulated. This is one of the most important things the nice people on this forum taught me. Not knowing any better I had my UTH unregulated at first and I'm so glad someone informed me that was bad practice. Luckily I followed the instructions in the package that explicitly says NOT to put it under the tank so I had it on the side like a dufus haha. Must be a liability issue or something. It's called an "under tank heater" after all. For curiosity sake I left it plugged straight in to the wall and was at 107F and still slowly climbing when I unplugged it.