If your using 32qt tubs in a rack and setting the temp to 90 and your probe sensor is set over the hot side your tub in the front on your cool side should be in the mid 80s. A 32qt tub isnt alot of real estate to have a dramatic fluctuation in temps. My cb70 racks are set at 90 and the fronts of the tubs sit at about 85. Ambient temps in my snake rooms are 82 degrees. But i could drop it to the high 70s and the tubs will still stay the same. When night dropping i keep the ambient temps in the room to 80 so i get a 10 degree drop during cooling cycles. I do tgis year round cause i have 3 different breeding schedules so i can breed year round