Grow Flow Ebb & Flow 12-site 2 Gal Complete Kit Active Aqua’s Grow Flow is the most efficient ebb & flow system on the market. With the Grow Flow’s easy-to-program controller unit, you can pretty much "set it and forget it." And since your pumps are only pumping a short time each day, the system is extremely reliable and efficient. Just set the fill and drain cycles, and the controller unit does the rest! As for safety, the ... — LTL Shipping Required. — Ships from HF: OR, CA, CO, MI, PA USA....more info.