Plastic Tub and UTH Help

[KMG]

The interior tub temp is not getting over 75F.
I didn't put a thermostat probe on the outside under the UTH because the UTH says to make sure there's no air bubbles and I figured having a piece of metal on a hot surface was a bad idea. Also the Zilla probe is really really big.

A uth is not meant to heat the air. They are to create a hotspot for the snake to lay on.

Your best bet is to remove the uth from the side and do as I said above with foil. Then use the foil tape to secure the uth to the bottom of the tub. After that Id secure the probe to the bottom of the uth as I explained above.

What is the temp in the tub and what are you using to measure it?