Alright so, a little background.. I have my BP in a 41 qt tub with 2' of 11" flexwatt. Her tub has been on my counter and I have never had a problem with her temps. The reason I got 2' of flexwatt is because I plan on getting a young Dumeril's boa, and putting it in a spare 28qt tub I have, and using the same strip of flexwatt for my BP, and my Dumeril's since they use about the same temps.

My problem, I set the tubs on the floor on a large piece of cardboard because I have no more counter space, (idk why but I just don't trust it directly on the carpet) but my temps started skyrocketing! I had the thermostat set at 91 degrees, but my acu-rite was reading 97!! ( dont worry i took my snake out before i started tinkering with it) The setup looks kind of like the "pi" symbol if that helps. I put the thermostat probe directly between the two tubs, taped directly to the flexwatt. so it is setup like a little 2 tub rack.

Is the cardboard affecting the flexwatt somehow?? Or maybe is my acu-rite messing up? I can post pictures if needed.