Define Constant Flow Aquaponics

[Sylvia Bernstein]

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

So, how would you define constant flow based aquaponics in 50 words or less?  What are the advantages and disadvantages?

[RupertofOZ]

Do you mean constant flow...or constant flood???...

An example of a constant flow system might include DWC raft systems... NFT.... or even stream fed raceway systems...

 

Even Chop/ChopII systems ... could be considered "constant flow".... but obviously through siphon drainage of the grow beds... are better defined as "flood & drain"...

 

Whereas "constant flood"... while a constant flow technique.... involves a set water level... usually set by standpipe

[Ricky Flickenger]

constant flow systems have a consistent flow of water, as opposed to pumps on a timer or with timed drainage systems (bell siphons). The water comes in at a constant rate & leaves at a constant rate - keeping the water at a pre determined level.

[RupertofOZ]

Probably covers all bases Ricky...

[Ricky Flickenger]

hopefully didn.t leave anything out...50 words or less is limiting, lol

[Jesse Hull]

I think the defining variable is that the roots are constantly submerged in a flow of aerated (nutrient) solution moving from one end of the system to another.  

Then define sub categories.  Constant flow could mean run-to-waste, partial run-to-waste or recirculating.

[RupertofOZ]

Yes the need for aeration is a key factor that should be included in any definition of any implmentation of a constant flow system...

[TCLynx]

Yes this one can be confusing since some one might say constant flow meaning "constant pumping" (which could include everything except timed flood and drain.)

Constant flow might also cover NFT, DWC and Constant Flood (Constant flood does work) or constant flow with the drained bed (more like constant trickle) which some people have tried and discovered doesn't work very well.

I try to be very descriptive when explaining things siphon flood and drain systems are normally also constant flow (at least into the grow beds) I don't really recommend the use of timers and siphons together, especially if you are also trying to do a sequencing and I definitely don't recommend siphons in conjunction with sequencing valves.

So I know this was longer than the definition but I think Constant Flow needs to be defined along with Constant Flood in order to make sure people know the difference.

[Sylvia Bernstein]

OK...I'll admit that this one messes me up as well.  So Constant Flow is really what happens in an NFT or DWC system, while Constant Flood is somehow different, and perhaps could be stretched to what is doing on in a media bed with a siphon?  I think of that as Flood and Drain, though...the siphon is providing the draining action in a media bed vs just shutting off the pump and letting it drain.  Is there really ever a media bed situation where the be is constantly flooded without being drained?

[Ricky Flickenger]

yes, my systems...they drain...but only over the top...the water level never goes below the media.

[TCLynx]

Yes, there are constant flood media beds out there (BYAP has actually been running side by side trials for the past year with one timed flood and drain bed, one siphon flood and drain bed and one constant flood bed.)

They all seem to work.

The banana tree in my big system was in a bed that was constant flood and my water chestnut/watercress beds are also constant flood.

[Sylvia Bernstein]

So does that mean there is a constant level of water in a media bed - say 8 - 10" in a 12" media bed - that is always there and you just aerate it?

[Ricky Flickenger]

one of my filters is aerated from below...the others seem to have no problems with O2 (and I haven't noticed a difference between these) that i.ve seen. they drain back down into the tankfrom a height to help break up surface tension and introduce O2 into the system again.