Define Flood and Drain Aquaponics

[Sylvia Bernstein]

The results of this discussion will form the definition of Flood and Drain Based Aquaponic Gardening on our Community Glossary of Terms. http://aquaponicscommunity.com/page/aquaponics-glossary-of-terms

So, how would you define Flood and Drain based aquaponics in 50 words or less?  What are it's advantages and disadvantages?  Is it the same thing as Ebb and Flow?

[TCLynx]

Flood and Drain is the same as Ebb and Flow.

It is where the plant growing space is allowed to flood and then drain either by the use of a pump on a timer to fill the bed quickly and then allow it to drain slowly while the pump is off or by the use of a siphon or other intermittent outflow device where the bed is constantly filling and then the siphon will drain the bed quickly.

Advantages of flood and drain include providing ample oxygen to plant roots and bio filter bacteria without the need of extra aeration.  Many plants like some dry time especially if the water is not super aerated.

Disadvantages, Water level needs to fluctuate in the system to provide the water for flood and drain.  Flood and drain offers more media to air then media to water interface which can have an exaggerated heat exchange effect on water temperatures.

[RupertofOZ]

"Flood and Drain is the same as Ebb and Flow."...

Not necessarily... in hydroponics many "ebb and flow" systems are filled from the bottom up.. and drain back through a single screened inlet/outlet pipe.. (often with a seperate overflow pipe.. to set max height... like an overflow standpipe)...

Ebb and Flow almost always uses a timer... but never a siphon...

 

Many hydroponic suppliers that attempt "aquaponics systems"... mistakenly often build "ebb and flow" grow beds... rather than true "flood & drain" systems...

[Sylvia Bernstein]

Interesting, Rupert.  I had always thought they were identical as well.  So given how you are defining "ebb and flow" how would you differentiate "flood and drain"?

[TCLynx]

Well I think they are still much the same, only real differences is in a hydro ebb and flow tray you are usually pumping up through the bottom of the tray and then when the pump turns off, you are draining back down through the pump.

Flood and Drain Aquaponics could do that but most people prefer not to let the solids come back down into the tank through the pump so most of the time Aquaponics pumps into the top of the bed and then lets the bed drain through a different drain, usually in a different location of the bed.  Flood and drain aquaponics can be accomplished via timers and a stand pipe drain, or one might let the pump run constantly and the flood and drain is accomplished by siphon or other automatic draining once the bed reaches flood height.

(I would then probably add some info about media bed aquaponics and it's benefits to go with the flood and drain description.)