UTH and temp gun reading different temps

I put my little guy in a tub and I am having some trouble now. The UTH is set to 94, but when I use a temp gun to confirm it, the temp gun says it's only 81 degrees. I'm not sure which one to believe! There is a sheet of paper towel between my snake and the tub/uth, so I don't think the substrate is affecting my temps. What do you think? Which one is right?

Probably both. If your tstat probe is mounted correctly outside the tub on the uth it is telling you what the uth is at. Using the temp gun inside the tub on top of a paper towel the temp gun will give you that temp. If the paper towel is not being weighted down and staying in contact with the tub floor it will not reach the same temp.

What is the temp of the tub floor? That is what you should be checking.

The tub floor is reading at 82. Should I raise my UTH higher or keep it as 94 to be safe?

I don't think you should be loosing that much heat. Is the uth not completely flat on the tub bottom?

It is common to have your tstat set higher than desired to reach the hotspot temp you need.

Maybe Im picturing it wrong in my head. Maybe explaining it more or posting a pic would help me help you.

I found a thread on here about how to set up a tub that isn't in a rack system. I have 10-20 gallon uth on a therm on the hot side. I took the therm probe and put it in the middle of the uth and then applied it to the bottom of the tub. I suppose a clearer way of saying this is, it's sandwiched between the tub and the uth. I then took aluminum looking tape and put it all the way around the uth, just to make sure it was really close fit. The cold side has a heat lamp about 6 inches from the top ( 3 small holes allowing the heat to come thru ) that is keeping the cold temps correct. My ambient temp that is being picked up by my acurite is saying that it's 85 in the hot hide. It's a mess :( Thanks for taking the time to help me though. I appreciate it.

I bet the uth has a small gap between it and the tub bottom and is causing some heat to be lost. Its not a big deal.

You can bump up the temp of the tstat to get the tub floor where you want it. Just do it very slowly and let it settle for a few hours before making another adjustment.

In a glass tank I have my tstat has to be set just over a hundred to give me a 88-90 hotspot because of the lost heat going through the cage bottom.

Wow that's insane Heat loss threw that glass.. With my t8 I had it set to 94 and over time this setting went down to 90 as the pvc material heated up now it stays at 90-91 running at like 25%

If you put the probe sandwiched between the UTH and the glass, and put it in the middle, then a lot of the UTH will not be contacting the glass, for this reason I sandwiched my probe on a corner of the uth, to avoid that issue.

What type of UTH?

I also found my temp gun and UTH probe read differently quite often, just the technology but it shouldn't be that different...

Switch to aspen bedding. I had the same problem a week an a half ago. Seething was the same, 94 tstat for the heat lost through the tub. 80 degree paper towel. The aspen allows you to set tstat at like 93 and get a 91 degree hotspot. Surface temps of aspen will be like 80 but the snake will just push the aspen around so they can get to the 90 degrees. only downside is it takes an extra minute to clean. Switch to aspen.

Also what temp gun are you using? I have a 412 and it is usually spot on with my accurite and herpstat maybe -1/+1 at times.

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