Rack heat issues

I have a c serpents v28 rack rack and a ve 100 thermostat. I have my probe placed on the corner of the middle rack with the electric tape holding it down and the probe not tapped. My thermostat is set at 92. My top rack is around 86/87 but the bottom can get up to 94. Any suggestions?

Check the tubs to ensure they're not bowed or the floor isn't warped so some have a wider air gap between the tub and heat tape than others. You can either move the tubs around to see if the heat discrepancy follows the tub or put something heavy (like books) over the heat tape in all the tubs to simulate the weight of a snake lying on the heat, and then get your temperature readings.

Will do