Flood and Drain Kit


In stock


The Flood and Drain Kit is used in Flood and Drain systems (also known as Ebb and Flow) where the nutrient is fed from beneath. This process floods the root zone to a pre-determined maximum level after which all the nutrient rich water is allowed to drain back into the reservoir. This process is controlled by a pump, timer and the Flood and Drain Kit which has an ‘inlet’ and ‘overflow’ device.

–  ‘Inlet’:  This also serves as the drain outlet. It is positioned as close as possible to the base of the flood & drain tray. Once pumping stops, the nutrient rich water is able to fully drain into the reservoir via the inlet and pump. Complete drainage is necessary to prevent water-logging.

–  ‘Overflow’:  This is positioned at the maximum desired flood height. This means pumping can only flood to the height of the overflow. To maximize feeding and flushing of the root zone this valve should be set as high as possible. However, if a medium is used, avoid wetting its top surface otherwise excessive disease, pest and algal problems can occur.

The most suitable media for flood & drain is Leca.

Advantages to Flood & Drain systems

–  The flooding action helps prevent salt build-up in the root zone and achieves uniform root zone pH and conductivity.

–  Flooding purges stale (oxygen deficient) air from the root zone. Drainage draws fresh air back into the medium.

– Efficient use of water and energy

Flood and Drain Kit includes:

  • 3 extensions
  • 2 screens
  • 12mm fill and drain fitting with nut and washer
  • 20mm overflow fitting with nut and washer

How it works

ebb/flow system cut-away

How to build it
What you need:
Flood and Drain Kit
Hole saw – 32mm

* The pump needs to be big enough to lift the water to the to tray but not too big or you will have a fountain! Most pumps have a measurement of how high they will pump. The tray must be above the reservoir so when the pump turns off, the water will flow back down through the pump. You can place the tray directly on top of the reservoir or make a stand for the tray and put the reservoir underneath.

You can adjust the water level with 3 spacers included. Each spacer will increase water level. Top screens prevent Leca and other debris blocking the pumps and fittings.

The overflow fitting may need to be adjusted to work in conjunction with the final fill height of the Leca…… if the is set too high, the growing medium may “float”, causing plants to dislodge and tip over, or even worse, the tray might overflow!

The timer setup should typically be 5-12 times during the day (depending on temperature) and fewer to none during the night.


Flood and Drain