Ok, I've been looking around for the answer to this one for awhile but can't find much. I have a cornsnake and a western hognose. Where should I have the thermostate probe placed? Right on the glass above the uth or on top of the substrate? My temps are around 82-86 degrees when placed on the glass. But of course I don't get that 90-some degree hot spot. Also, I can't get my cool side temps up. They are staying around 66-70. I have a towel over the screen to try and hold heat in but it didn't make a difference. And of course my hognose seems to like to chill over on the cool side all the time Any advice? Thanks so much!

Erin