The Ebb & Gro (comes with 12 planters and is expandable to 48+) is the most versatile ebb & flow system on the market. With many growers going from large numbers of small plants to fewer, larger ones, the Ebb & Gro fits the bill! It is a simple system that uses 2 pumps and gravity to flood and drain the planters about 3 or 4 times per day.