Backyard Aquaponics
A place to discuss aquaponics

Will the nutrient levels in the water after flowing thriough the grave grow beds be sufficient to utilize a NTF system as a return to the fish tank?

i think the consensus has been no

I don't see why not, Steve. Please clarify.

As the gravel GB's both support plants and process the NO2, NO3 if the fish bioload is high enough I do not see why an NFT after the gravel GB's would not work. It would all depend on ratios (fish/plants) and nutrients available.

Never attempted it but I had thought the consensious was yes its workable.

I had the impression that a gravel bed before any NFT or DWC was a good thing. Of course if you have a 2:1 ratio of gravel to tank and the gravel is heavily planted, then there might not be enough nutrients to go around. If the ratio is low, then the extra plants to take up nutrient might be a good thing but it is possible that the bacteria might not be able to keep up with a heavy fish load.

Many people seem to believe that the solids in the grow bed are of great value to the plants though and question if the NFT is worth the trouble.

Yes it works. Have the NFT after the gravel beds so that the gravel filters out the solids. Organic solids going through the NFT will stick to and choke the roots.

it is important that you have enough available nutrients. IMHO, the best way is to have 2 systems: One that has all solids removed and seperate biofiltration then nutrient removal through nft planted channels with green leafies and system 2 with gravel growbeds with fruiting plants. We have found that while running low nute levels, the nft channel just don't get enough grunt.

I think that's the key. My NFT was doing OK but not as good as I had hoped, that is until I started to wind it up a bit. Now there's more fish, more nutes, and more growth.

HA! a test! you all passed

i thought the question was

Will the nutrient levels in the water after flowing thriough the grave grow beds be TOO LOW to utilize a NTF system as a return to the fish tank?

nothing to do with speed reading.

shut up, VB.

Nice save Steve ..... ROFL

I would like to weigh into this till recently i have been running kind of 2 systems one 2000 litre ft 4 grow beds 1000 litre running 1 sump after the grow beds with its own pump running the nft and trout tank also a line running replacing 10 litres per hr to a nother 200litre sump outside the glass house running 4 beds 1000 litre running 15 min on 2 hrs off
So summing up the glass house is running on double filtered water the additional neutrient is 20 litre filtered water top up [straight in the top whats not used overflows to ft] the glasshouse is growing better [heat i suspect]

Yes this is an established system and has not been touched just added to
And theres a large collony of worms adding there bit

Thanks everyone. Starting to build now. Will have pictures soon.

I guess the true answer would be, "When in doubt, add more fish."