BTW thanks for the input so far guys! I do have one more question which should be a little less vague than the first... If I use back heat and decide to change the tub size (I believe there is a larger and smaller one that are the same height as the 32QT) will it be harder to maintain a similar temperature? Will sliding the tubs closer to/farther from the back wall of the rack allow me to correct any differences in temperature? That is my main concern about using the back heat.