Thanks! Well, I am shopping around for a smaller RHP. When I get it, I'll disconnect the heat pad and see what happens! My plan is to build up the substrate on one side and find a hide material that is more conductive of heat, see if I can't get it to 89-91 in the hide.

From experience, I find the RHP VERY effective at heating the glass tank (note that it does have a wood lid and cork board on the back). Mine is 80W and it's barely on (the indicator light flickers), and it adds about 10 degrees to the tank. It goes up a smidge higher in the winter when it's colder in the room, but still barely. Even in a larger tank, I can't imagine how hot it would get at full temp. I'm shopping for a 40W at the moment.