Ok so I just got a 4 tub rack system from CSerpents. It came with 3” flexwatt preinstalled and recessed towards the back of each shelf. I’m using a VE-200 to control it with the probe right on the flexwatt.

Initially, I set everything up and put the thermometer probes on the floor of the tubs right over where the flexwatt is located. At the time, I did not add any substrate, hides or water dish and definitely no snakes yet. I want to ensure stable temps first.

With the flexwatt being recessed and the tubs having a very slight lip on the bottom, there is what i estimate to be a 1/8-3/16 inch gap between the flexwatt and the bottom of the tub. I had to eventually set the VE-200 to 103 F in order to get the temperature probe from the thermometer to read between 90-91 and hold steady. I left it like that for 24 hours and constantly checked to ensure the temps were staying steady.

Once that was confirmed, I took one of the tubs (the 3rd one down from the top) and added a little reptile prime (thin layer, like 1/4 inch), hide box and water dish. Again, the thermometer probe is suction cupped to the floor of the tub directly over the flexwatt. In that one tub, and that tub only, after sitting overnight, the thermometer is reading 87.1 degrees. All of the other tubs, which are still empty except for thermometer probes, are reading between 90.1 - 91 degrees. Checking with a temp gun is coming up with similar readings (maybe 0.1-0.3 degree difference from thermometer probe reading). I have been relying more on the thermometer reading because the tubs are translucent, so when I slide the tub out a bit to shoot it with the gun, is it reading the temp from the floor of the tub or passing through to the shelf, or a combination?

Ambient temps are good (78-79) and humidity is 60-64%. It’s just the floor hot spot temps that are throwing me for a loop.

My my theory is that the temps are actually good and that maybe some small pieces of reptile prime are getting between the thermometer probe and floor of the tub which is absorbing some of the heat and throwing the reading off a little bit. I just want to be sure.

Any thoughts or suggestions?