What is Ebb & Flow/ Flood & Drain system?
Ebb and Flow hydroponic systems are popular among hydroponic gardeners. In this system, plants are placed in large grow beds filled with growing medium. The growing bed is filled with nutrient solution until it reaches a certain point. The drain is the one which allows the water to raise up to a few inches below the top of the grow medium so that overflowing does not occur. A timer controls the power to the water pump. After running for a time period, which is predetermined, the timer shuts down the pump which makes the water to go back through the pump, draining the grow bed completely.
This kind of hydroponic system can also be set up to drain with an automatic drain which removes the need of the pump which has to be set up with the timer. Automatic drains will allow you to flood and drain the system quickly and frequently. This increases nutrients, oxygen and growth.