Hello, I have two racks, one rack with 41 qt tubs (with Herpstat1 thermostat and heat cable) and the other with 28 qt tubs (with Vivarium Electronic and 3" flexwatt heat tape but I should get the Herpstat1 tomorrow).

I'm curious, what is the difference in degrees?

On my 41 qt tub rack, I get about 6 degrees difference. I use paper towel as substrate and I put two layers of paper towel. Should I just use one?

With the 28 qt tub, I have it set on 98 degrees to get 91. That's 7 degrees difference. Normal?