Backyard Aquaponics
A place to discuss aquaponics

I was hoping create a thread dedicated to NFT AP. I know it is not a very favored technique however I feel it is still viable for those with a lack of space or in my situation in a major metropolitan area. I would love to hear feedback and results with regards to channel size, types of crops successfully grown, hardware, etc. As I have learned through members here, pre-filtration for solids break up is a must so please share any techniques you may have tried. Are you using rockwool and netpots or another technique? Do you germinate your seedlings till the roots are long enough to be in the water once introduced to the channel, or do you put them in sooner and hand water them for a few days until the roots are in the water? Do some crops with their root structures filter water better than others? Are you using one pump for multiple channels? If so how did you design your manifold? Just looking for more feedback on various results from NFT techniques. Hopefully pics too.

I can't say that I'm entirely convinced that NFT actually takes any less space to grow the same amount of plants as any other method. About the only thing you are really saving is the weight of the gravel which I can kinda understand in a city situation (hauling gravel up the stairs to the roof or a balcony is not my idea of a fun activity.) The space thing, when dealing with tubes or channels, the space for the roots is finite and they will stretch along the tube rather than in all directions and there will be overflows and messes to clean up from time to time when the roots get out of hand. You still need a bio-filter and a solids filter. There are bio-filter media out there that can do the job in far smaller spaces than gravel beds but they do usually require separate solids filtering and cleaning/replacement of the solids filtering material regularly. So, there is some space for the solids filters and bio-filters where plants are not getting to grow. (These are the primary reasons that most of us here on a backyard scale prefer flood and drain gravel beds-less maintenance and cleaning to do.)

Rupert probably has the most experience with NFT of the threads here on the Forum since he is running an almost commercial scale Hydroponics set up in his yard.

I have only minimal experience with NFT but I do have two long pipes attached to my system. (Now I'm wishing I had an index or table of contents to help me find the right point in my system thread to link here.)
Ok so here is the section of my thread where I start doing the NFT.
http://backyardaquaponics.com/forum/viewtopic.php?p=182430#p182430

My NFT pipes are mostly 4" pipes with only a small section of 3" pipe that was left over from a previous attempt.
The water going to the Header tank feeding the NFT pipes has been filtered through two levels of gravel filled grow beds.
There are still small particles that manage to get through everything and I probably need another layer of filtering but I don't know what to use without risking clogging. I have noticed gunking roots and some rotting roots on some plants in the NFT probably because of the solids.
Lately, I noticed that the water level in the pipe was way high up near the start of the flow so I had to pull plants out and trim off huge amounts of root mass that were clogging the 4" pipe and almost causing overflowing through the plant holes.

What grows well for me in NFT
Basil
New Zeland Spinach
Maybe strawberries?
I expect lettuces will do fine in NFT but cooler weather is required to grow lettuce and it's been hot since I set up the pipes.

I have used the NFT pipes to root cuttings of tomato plants just by sticking the cutting down into the holes and leaving the top propped out of the hole.

In NFT or even DWC there is the whole process of getting seeds going and then transplanting into the net pots etc. I'm not patient enough to do it that way. And I would never remember to top water the net pots often enough to get seeds and tiny seedlings to survive (takes more than 3 days to get the roots down out the bottom of the net pot you know.) So, I came up with a method using a wick so that I can plant the seeds directly into my cups and they can still germinate.
My "net pots" are actually little yogurt cups with a rim that will hold them in the holes I cut. The wicks are from a bright white rayon mop head. Here is a link to the section of my thread where I show those cups, the wick and planting.
http://backyardaquaponics.com/forum/viewtopic.php?p=183096#p183096

My only issue now is what am I supposed to do with that much basil!!!!!!! I think this month the worms get a bin full of basil. (Just and FYI, you don't need a line of basil that long for household consumption so unless you are supplying a restaurant, you will be composting lots of basil. I need something in using up nutrients over summer so I haven't pulled the basil out of the system though we only need a couple plants for our own use.

Basil .....,never too much ,, make Pesto:)
If pine-nuts are expensive in your area , replace them with Macadamian nuts.

TCLynx, excellent post, thanks for the input. Having grown basil and lettuce I have not yet experienced root balls big enough to clog the pipes. I am using 3” for all. Going vertical I can grow 99 heads of lettuce and or basil in approximately 18 sq. ft. Going vertical prohibits ebb and flow due to the weight.

I was also wondering if clear tubes/channels were used, if it would help monitoring or root developement and possible solids build up. I think that if the filtration was engineered very well and was easy to maintain, it could be controlled quite efficiently, however, I have not seen or thought of the ideal solution.

Anyone else growing anything else other than lettuce and basil? We have snap peas and a pumpkin started now.

personally i think its the whole ford chevy thing....

some people like nft - chevy
some people like ebb and flow - ford

both serve thier perpose and have up sides and down sides.

chevy's never die... they just go faster =)

Nope... clear channels are definitely never used... exposure of the nutrients to light would result in algael growth... deplete oxygen (vital for the plants) from the water... heat the water, possibly causing salt precipitation... further lowering oxygenation of the water.. and affecting the roots...

Typically... commercial NFT channels are 150 x 75mm...sometimes 150 x 50mm for starting seedlings or plugs... and fast growing spreading root ball plants like lettuce and Asian greens...

In the pic below... you'll see one of my tables has a run of the smaller channel on each side for the purpose of starting the root development of the seedling plugs... rather than having to adjust the flow rate/height in the channels... (you'll also notice that the channel holes a spaced at half the distance of the normal spacing 300mm)...

Each channel should be fed by at least one 10mm "spagetti" tube...

Supplied from a common manifold... typically 25mm... fed from below into a tee piece... and the line capped at both ends...

The supply line should be fitted with a ball valve (green)... to allow control to vary the flow rate/height within the channels...

Taller plants, or plants that develope large root mass... may use channels known as "Jumbo" or "Polar".... 200-300 x 100mm...

i.e capsicums ("peppers") or tomatoes

Sometimes these channels are single run configuration... either slightly raised or laying on the ground... somewhat like the "rockwool slab" style of hydroponics...

This pic shows capsicums growing in rockwool slabs... but "jumbo" channels would look the same..

And here are tomatos in jumbo gully... slightly raised..

And here's one of my tables from the previous post growing "green oak" lettuce..

Clear tubes might let you more easily monitor the roots until algae took over and stopped you seeing through the tubes. Roots don't much like light though and the algae/gunk in the tubes would probably be really ugly to look at.

I've got a few strawberry plants in the NFT as well as some new zeland spinach.

As to the snap peas and pumpkins. The peas may give you some trouble with the lighting as it grows up. The pumpkins, well it depends a bit on the variety but I expect you will have some challenges with the root mass there. Also, most pumpkins like to send rootlets down along the vine where it contacts the soil under normal growing conditions so I don't know how much it will like growing in an NFT situation. I once saw pictures of a situation where some one tried to grow a prize pumpkin hydroponically. They hooked up a hydroponic bin where ever the vine started putting down rootlets. I think by the end of the project they had over 10 bins and buckets hooked up and all were completely filled with root mass and I'm not sure if they ever got much in the way of fruit from the plant. So, keep a close eye on the root mass of the pumpkin as it would suck to have to cut the pipe open to get the plant out of the system.

Just as a note to everyone (please correct me if I'm wrong here Rupe) the set ups that Rupe is showing pictures of here are Hydroponics set ups right? Not Aquaponics.

However, I believe I've heard that Rupe does top up his hydroponic tanks with filtered AP system water right?

Correct on both counts TCL... the pics are all NFT hydroponic systems...

I do use water from my aquaponics systems (filtered) as the nutrient base water... still adding hydroponic nutrients... but at a much lower level than traditional hydro nutrient mixes...

My system is being converted to run purely from aquaponics nutrients as of this week...

I don't know what I was thinking about the clear channels, thanks for the smack back to reality. My supply manifolds are 1/2 inch and feed tubes are also 1/2 inch to each channel with valves on each manifold. Looks like I am limited to leafy greens in my small 3" set up.

Rupert, are you selling some of that stuff? Looks like a very high yield set up.

The table of green oak was meant for a sale that didn't eventuate... but I pulled about 30kg of basil off a table during summer...

And there's a table of Italian Parsley destined for sale currently growing...

Along with a half a table of baby cos lettuce... the other half will be planted out this week..

Looks very interesting. I am meeting with someone tomorrow who I have know for a few years. Here in the US he is a legend in the business world and his connections are second to none. During our last meeting, I told him what I was up to, which turned into a 3 hour conversation with him asking all kinds of questions. He is very interested in contributing to start up a large commercial operation here in Chicago. He understands I am no expert. His funding availability is nearly limitless, no joke. We would be growing indoors, possibly greenhouses or modified warehouse. Hence my interest in NFT, and using AP in some aeroponics setups. The larger NFT tubes look promising for larger rootballs. Great info, keep it coming.

Please Rupe, share your info about the change over to pure AP for the NFT system. Stuff like the filtration and all that will help people here. Then will be really interested in some updates a few months down the line to see how it is doing over time.

As to what you are up to in Chicago, have you checked out Growing Power yet?
http://www.growingpower.org/

Yes, very framiliar with Growing Power as they have an operation here in Chicago as well, although not AP. Their claims of 1,000,000 pounds of food per year are a bit elevated though. Their use of compost for heat in the winter is fantastic. Their vertical concept is hanging baskets of compost grow above the AP grow beds.