please help--thermostat reading vs thermometer reading

[Apple_cafe]

Thank you for the info, I will get a different thermometer to see if mine are just off and try turning the hot side temps down a bit. I’m not familiar with forums like this so I don’t really know how to upload a photo via URL so I’ll do my best to explain it a little better.
The CHE thermostat probes are both inside the tub, poking in through holes I drilled. Both thermometers are facing out, against the plastic at the front of the tank.
The hole for the cooler CHE probe is a few inches directly above where I stuck the thermometer.
The hole for the hot side probe is a similar height but drilled into the back side of the tub. So it’s directly across the tub from the thermometer, a few inches up. The wires snake in and the probes themselves end up just a little bit higher than where the thermometers are placed.

No rack— the tub is sitting on a shelf in the corner of my office, with two out of the four sides against a wall, the other two open to the room. i got it because I heard they hold heat/humidity better than glass aquariums (which is what I started out with for the first day or so). I plan on upgrading him to a more permanent PVC enclosure once he outgrows this tub.

also, as I was doing a spot check tonight i saw that he finally pooped, in his hot hide no less. So that makes me feel a little better knowing that he’s digesting right.

I'm trying to create a picture in my mind of thermometer/probe placement. Do you mean that the thermostat probe is on the outside of the tub? Or do you mean they are both inside, but on opposite walls? Is the CHE central to the thermostat probe and thermometer or closer to one? Have you double checked with a different thermometer to make sure the one isn't reading off by several degrees?

If he is sleeping in the cool side hide most of the time, I feel like the ambient might be a little on the high side vs not hot enough. I wouldn't be super worried that it's way out of range either though, because he would likely be in his water dish to cool off or nose rubbing trying to escape.

Is this tub in a rack or just loose? It might be that the side the thermometer is on is cooling off more than the side the probe is on because of where it's placed in the room. For example, if you have it in a shelf where the length of the tub is against the back wall of the shelf, and that back wall is where the probe is? Having the tub with the cool end facing out is the most ideal for temp gradient, though it's not the best to observe him obviously. The only way to really have the best of both worlds is to have a space heater keeping the entire room at a more acceptable temp.

If I'm misunderstanding how things are placed, feel free to correct me. Picture would help a lot to understand the placement of things.