Ebb and Flow Hydroponic System also known as flood and drain. It presupposes the use of the pots placed on a plastic tray for the plants growing. The pots are filled with perlite (expanded clay pebbles as Hydroton, or Rockwool), which supports the roots of the plants. The tray is situated above the reservoir with nutrient solution. This is important, because such placement ensures the work of the whole system, which is actually triggered by gravity. 

 

Nutrient solution from the reservoir fills the tray with plants pots due to the work of the pump, which is attached to the bottom of the tray. Overflow fitting, fixed in the tray at a height that a gardener predetermines himself, does not allow too much water to enter the vessel. When the pump is off, all the water flows back into the reservoir through the pump, and later it is used to water the plants again.

 

The procedure of plants watering repeats several times a day, and it is controlled by a timer. Usually, these are short one-hour cycles. However, a gardener may choose some other schedule, taking into account the type and size of the grown plants, environmental conditions, as well as the hydroponic system used.

 

Ebb and flow is suitable for high density planting. One of its main benefits is good oxygenating of plants roots. First of all, when filling the tray, water pushes out old air with carbon dioxide from around the roots. Later, when it goes back down into the reservoir, fresh, oxygen rich air is delivered to the roots. This air is available for the roots till the next irrigation cycle. Moreover, when water runs down and reaches the reservoir, it splashes, which creates its additional aeration in this hydroponic system.