Hypothetical system

[Eric Warwick]

As always I was thinking about aquaponics and I thought of an idea of a chift pist type system. ( or at least I think) How it works is a; gravel sump tank comes out of a overflow and goes through the entire grow bed with another overflow, then a raft system gains water from  the overflow from the sump/gravel bed and uses a water pump to go back to the fish tank through N.F.T. . If this is crazy I understand, or if this is not an original idea then good luck to the inventor. I don't have a diagram as it is just a simple not well done drawing.

[Chi Ma]

Check this link out. 

http://www.ecofilms.com.au/2010/10/28/aquaponics-chop2-revealed/

[Eric Warwick]

Thanks; I was actually thinking of more of a circular system, but the chop 2 is definitely a well designed way of doing aquaponics. I think a chop system is similar but not the same. The gravel bed is higher than the raft and a pump bring water from the raft up and into nft which goes into the fish tank. Please tell me if more clarification is needed. Now of to find that drawing. :)

[Sylvia Bernstein]

I, for one, am having a hard time wrapping my brain around what you are saying, Eric.  Maybe it was the wine with dinner...

[TCLynx]

Sounds like tall fish tank overflows by SLO (solids lifting overflow) into a grow bed who's top is just a bit lover than the water level in fish tank and that bed (perhaps constant flow/flood) drains into the raft tank which is also the sump tank where the pump lifts the water up to NFT pipes that drain back into the fish tank.

 

I would probably not call the grow bed a gravel sump because it isn't the lowest place, nor is the pump drawing the water from it.  Sounds like a reasonable CHIFT PIST design to me.  It isn't a new idea but I doubt anyone can really claim to be the inventor of the idea.

[Eric Warwick]

It is like gravity fed system with a pump in the deep water culture. First fish tank, then gravity feeds water to a gravel bed, (lower) then a lower raft bed, which pumps water through nft to the fish tank above. I'll try and draw a diagram. 

Sylvia Bernstein said:

I, for one, am having a hard time wrapping my brain around what you are saying, Eric.  Maybe it was the wine with dinner...

[Eric Warwick]

This is my 5 min diagram. Hope it is helpful.

 

[Averan]

that could work, but the constant-flood media bed would not be as effective at bio-filtration as a flood&drain media bed.  you might consider adding a 12" deep media bed directly over the constant-flood grow bed so that the fish tank overflows there first and then drains down into the grow bed via a f&d siphon.  that way you have an aerated media bed (with worms) to provide oxygen and aerobic digestion of solids in addition to the grow bed that (without any added aeration) would likely just be a solid-settling tank.

[TCLynx]

Agree, a flood and drain media bed and pushing the NFT up higher will have some benefits.

[Chris Smith]

Keep in mind that in this configuration the DWC trough becomes a sump and the water level will fluctuate with evaporation.

[TCLynx]

Very good point Chris.  And I might also note that a DWC acting as a sump should probably be a little deeper than normal and placement of things like the pump, top up valve, and inflow plumbing should be thought out so they don't impede the rafts floating up and down with the water fluctuations.

Also a fluctuating water level in a raft bed will have implications to the air flow balancing so if the fluctuations will be more than minimal, that raft bed/sump might need it's own air pump rather than sharing with the rest of the system.

[Eric Warwick]

Don't all DWC beds need their own air-pumps?

TCLynx said:

Very good point Chris.  And I might also note that a DWC acting as a sump should probably be a little deeper than normal and placement of things like the pump, top up valve, and inflow plumbing should be thought out so they don't impede the rafts floating up and down with the water fluctuations.

Also a fluctuating water level in a raft bed will have implications to the air flow balancing so if the fluctuations will be more than minimal, that raft bed/sump might need it's own air pump rather than sharing with the rest of the system.

[TCLynx]

A DWC beds need aeration but not necessarily their own pump.  You might have a single large blower supplying air for a large aquaponics operation but if a particular tank or bed is having extreme water level fluctuations and it is being fed by the same air pump as other tanks that are not fluctuating the amount of air flow out the various parts of the system could fluctuate in ways detrimental to other parts of the system since the valves balancing the air flow won't be getting adjusted according to the water level fluctuations.