I had a cheap thermostat for my uth and the temps shifted from 85 til about 93. I have an accurite temp. I checked out what a good thermostat was on here and everyone highly recommended the ranco or johnson. I spent 80 bucks and got the pre-wired ranco. My thermostat probe and the accurite probe are both under half inch of substrate(cypress mulch) directly on the glass above the uth. Guess what, my temps still change just like the cheap thermostat, 84 to about 91. Which one is junk, the accurite or ranco?