This is probably the cheapest way to do a 28qt tub rack. Go to Home Depot and buy a 96" x 24" sheet of melamine and have them cut it to 4x - 24 x 18 pieces and 6x - 24 x 4" pieces and buy a box of 2" wood screws. You'll need 48 screws. Use the 24x18 pieces for all 4 shelves, and the 4" pieces for the sides and back (2 per side and 2 in the back. Attach the 4 sides to the first shelf, flip it over, then use a 28qt and a 1/8" spacer board to lay lay your next shelf. Attach the 2nd shelf and repeat until all 4 shelves are attached. Finally attach the back boards and install flaxwatt. The total price should be $27 plus the flexwatt and thermostat. All my racks are solid melamine. It's heavy, but with only 3 tubs high it won't be too bad. Good luck!