You can build an Ebb and Flow system with like $20, not counting the pump and a half hour (not including silicone drying time). Two 28 quart bins and a large res that holds 15 gallons easily from Wal Mart. Then like 5 feet of 1" tubing and matching intake and drain nozzles from Lowes, and some silicone to seal it all off and you're good to go.