Quote Originally Posted by Neal View Post
Lift the tank up, or you can partially slide the side that has the uth out so you can shoot the uth directly. That'll give you a better idea.

Also keep in mind that even though it may be ideal, once the substrate is covering it, that also raises the temps because it basically insulates.
Hmm, so you mean that the temp the UTH is on the outside is the same temp as the thermostat/inside of UTH? Also, how then would I determine the temp at the hottest spot in the tank right above the UTH?