I have a 15qt Sterilite locking lid tub. The bottom of the tub is caved in in the middle in the shape of a square. I bought this new tub as a replacement to my old tub (a 15qt Rubbermaid tub with a ill-fitting lid and no locking features). I made the mistake of taking the sticky backing off of the UTH, and I have peeled it off a total of three times. I heard this may mess up the interworkings of the UTH itself. This is where my problem comes in. Since I've switched the tub, the temps went from staying a constant 90 to 84. I have a Hobbystat thermostat. I have had it set to 90, but the temperature stays at 84. I am using a digital thermometer on the warm side. The UTH is connected to the bottom of the tub, sort of on the "ridge" part. I have my UTH plugged into the thermostat, and the thermostat plugged in to the power outlet. The probe for the thermostat is taped to the bottom of the uth. So the order from top to bottom is: tub, uth, probe. I am not sure if it is:


  1. The shape of my tub, the ridges are making it difficult for the thermometer to get a good reading.
  2. The UTH fitting over the tub, the shape of the bottom of the tub (it caving in in the middle), since its not flat, the uth isn't properly sticking to the tub.
  3. My UTH might be messed up due to the fact that I have peeled it off three times
  4. The thermostat might be giving me problems, its set to 90 and seems to be working well, everything is plugged in correctly
  5. The thermometer might be broken and giving me wrong readings


When I feel the bottom of the tub it appears warm, but only in the middle where the bottom is flat, away from the ridges. On the edges of the tub, where the uth is taped, it is slightly cooler. I can provide pictures but I am at school right now so I would have to wait.

I am using paper towels as substrate right now. I do not have a ball python at the moment, but I plan on getting one on Saturday 12/13/14 at Phoenix Repticon. I've been preparing for this for a couple months, and I've done plenty of research. My cool side is currently at 78. My warm side used to be a solid 90, but now its only 84. Please help me solve this mystery! Again, I am willing to provide more details and pictures, I just want to get this figured out for the safety of my future snake.

Here are a few pictures of my set up.

Left is cool side, Right is warm side.

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Here is a picture with the lid on, the lid is pretty much the shape of the bottom side of the tub, so you can get an idea of the elevated ridges.

http://prntscr.com/5f3phc

Please help! Thank you!