Flood/Drain system

A plastic tray filled with plants (usually in pots), on top of a reservoir filled with nutrient solution. A pump in the reservoir is connected to the bottom of the tray. When the pump turns on, the tray fills with water. When the pump turns off, the water runs back down through the pump into the reservoir. The tray must be above the top of the reservoir so gravity pulls the water back down. An overflow fitting must be added in the tray to regulate the depth of the flood. When the water level reaches the top of the overflow, it runs back into the reservoir. The pump can be turned on with a timer. A system like this usually waters 3-4 times a day.