Backyard Aquaponics
A place to discuss aquaponics

Ok so we have 2 800 Gallon Fishtanks. I dont know alot about NFT systems but we have decided NFT is the easiest course of action and the cheapest in our situation. I know you have to have a adept filter but what would you recommend? For a system how big would a growbed have to be to break down the solids would it need more surface area or depth? Maybe not even a grow bed it could possibly be a gravity sand filter or a entire IBC of bioballs. Next we have the Plant to Fish Ratio. I was thinking about 1000 fish for this size and about 1250 heads of lettuce? Found this from just reading other topics. Im thinking of a A-Frame type setup like the one in the video below. And lastly Algae Growth this would not normally be a problem but the fish tanks on a concrete pad in direct sun almost they will be surrounded by a wooden structure but not enough to block all sunlight I know the Tilapia will eat the algae off the walls but im talking about the slimy stuff that will clog pipes and make a mess. Help would be greatly appreciated if you have done NFT please tell me some tips on how to run it.

https://www.youtube.com/watch?v=EJjAWF2DfWY

I'd go with 200 fish per FT, then have a RFF, and then a netting filter prior to your DWC bed.

I thought I read dwc, not nft. No experience with NFT. That video was hydro. You could have appx 135 basil in the same area with a dwc bed. Much less fittings, and from what I've read, more productive then NFT. Nft has issues with water temps nutrient and inconsistencies.

Dwc bed as a floating raft system? And the problem is we can inexpensively make these A Frames but would need a large DWC bed but it might be possible. What about filtration any input on that? I thought you needed a large growbed for bacteria surface area. Also how many plants would 400 tilapia provide for? And the video would work for aquaponics to

NfT or ‘ nutrient film technique is a good system to use when space is limited.
My space is limited.
So last year I ran a water feed to two 2 mtre pipes. I had read that square pipes are better then round ( Mr Damage) I cut holes in the 6cm commercial drain pipes at 15 cm intervals. Perfect for 50 mm net cups. I used the commercial available ‘L’ joints to form a staircase.
First problem. I siliconed and taped the connectors but still had leaks.
In the UK they are 91.5* connectors . You can imagine the problems in alignment.
This was irrigated by the main pump on a 45/15 minute cycle.
With hindsight I could have chosen white pipe. I chose black. The tubes act as radiators so increase heat.
However I will again this summer attempt an NFT system.
First change was to add a dedicated pump on constant flow in the sump.
For me this meant increasing the sump capacity. Not applicable to all.
The next main obstacle was to eliminate the ‘commercial bends’.
I bought , end stops, on Ebay. Worked fine but not water tight. I did consider 3D printing but too expensive.
Stuck!
Two things changed everything. I found a 22mm to 4* 10 mm manifold in plastic.
This meant I could run my normal 22m supply line and then divide to feed the four NFT tubes, “ Independantly” They could now be on an incline and the fact that the end caps were not 100% water tight was not important. The dedicated pump from the sump ran through a ‘T” return line with a tap. This would enable me to control the flow. However I found that with the manifold horizontal to the supply pipe, flow was erratic. By adding an ‘L” and allowing the water to fall down to the manifold I got even flow.
I have now got 4 tubes at varying heights. 60 cm spacing.
Using 110 cm soil pipe I constructed a ‘trickle tower’ four slots cut into this pipe receive the four square NFT tubes. This is filled with bottle tops. It the flows on through a net filter and a bio filter to join back into the sump. ( More info on my blog)
Will the ‘trickle tower’ mitigate the radiator effect of the NFT tubes? I don’ know.
Will the various filters reduce the size of suspended solids ? I think so.
Am I having fun?
JUST A BIT!
( English understatement)

Thanks Titus but the really important stuff is the ratios of plants to fish, and the filter system. Would my system work if I went 2 800 gal FT-->4 26 gal RFF--> 275 gal IBC full of gravel --> DWC/NFT

I think if you look into costs a bit further you'll find that NFT is more expensive than a DIY DWC bed if cost is a major limiting factor.

Well we have plenty of pvc and wood laying around but we certainly do not have Expensive pond liner for a big long table and for Styrofoam

Hi
Let’s work backwards and play with a few numbers.
1200 lettuce. Under good conditions they will take about 4 weeks to grow.
So assuming continuos production about 300 per week.
Now either your family eat an awful lot of lettuce or this is a commercial setup.
Assume 15 cm per lettuce. 0.15 times 1200 = 180 meters. At say 3 feet per meter
540 feet of NFT tubing
Industry standards suggest a max length of 20 meters.
9 tubes. An A frame about 2.5 mtrs high and 20 long Say 7 ft high by 60 feet long.
Gut feeling too big! Split it in two.
You have two FT so two independent systems.
20 ltrs of wet gravel per fish. A full IBC 1000 ltrs 50 fish. There is a thread on here about a guy who used full IBC as filters( can’t remember name) but they can introduce their own complications.
K1 bio media about £1.6 per lt here in UK £1600 to fill an IBC Say $2000
If you are going commercial consider a drum filter. about $4000 from what Coachchris says.
If you are going commercial then you need a lot better advice than I can provide.

This is commercial setup but buying those bio balls are to expensive for our budget would pea gravel be better or lava rock? We can get lots of IBCs if needed we have 8 already.

How does fishnet work in a biofilter? Could I just use spools of fishing line?