Heres the rack i made. Holds 12qt, 28qt, and 41qt tubs. Uses 11" on all the shelves. The heat tape is ran across the back of the shelves for the 12 and 28qt tubs. The depth of the shelves allows me to move the tubs over the heat tape and place where its neccessary. The 41qt tubs run long wase and has the heat tape ran on just the one end of the shelf for the tub. Using the 11" on all the shelves lets me use a single thermostat for the entire rack. For a rack this size, it cost me $136.