Have anyone combined NFT with a spray bar yet?

[Kobus Jooste]

I want to add plant growing capacity to my micro system without really putting an extra burden on my water supply.  I have been designing for 110 mm NFT-style pipes with short rotation crops in them, and want to use an internal rigid pvc line (20 - 32 mm) drilled with a few small holes in the location of each pot.  The internal line will be located in such a manner that the water jets are aimed directly at the net pots/roots inside the larger pipe.

 

Has anyone tried something like this before?

[Kobus Jooste]

Some detail I did not put in.  The water will be filtered, and the spray line would be above root level, making it next to impossible for plants to clog it up.

[Sahib Punjabi]

Namaste Kobus,

 

I believe that this is similar to Aeroponics...I was going to try this by using the fine sprayers used in drip irrigation systems. I have one overhead spray line set up over my DWC raft system and used that a few months back when we reached over 90. It worked great as not only was I using filtered water (pump in milk carton with filters in Koi pond), the force of the water did not clog the sprayers.  I thought of trying exactly what you are suggesting in Phase II but as time & $ constraints are a reality, I am a little behind schedule. Still, when I have Phase II up and running, I certainly will share my experience. What I am not sure about yet is whether to have that on a continuous flow or on a timer.

 

God bless:-)

[Kobus Jooste]

I want to try timed spray to start with, but with a twist.  The test set-up will come into play in winter, and I want to have it functioning only by day.  I think the closed-in pipe will protect the roots through 10 hours of no spraying, or what do you think?

Sahib Punjabi said:

Namaste Kobus,

 

I believe that this is similar to Aeroponics...I was going to try this by using the fine sprayers used in drip irrigation systems. I have one overhead spray line set up over my DWC raft system and used that a few months back when we reached over 90. It worked great as not only was I using filtered water (pump in milk carton with filters in Koi pond), the force of the water did not clog the sprayers.  I thought of trying exactly what you are suggesting in Phase II but as time & $ constraints are a reality, I am a little behind schedule. Still, when I have Phase II up and running, I certainly will share my experience. What I am not sure about yet is whether to have that on a continuous flow or on a timer.

 

God bless:-)

[AJ Grottke]

Ive run these in hydroponics and they worked great; it is a commercial available product called "areoflo" i beleive..  I was not able to do a side-by-side with regular NFT though.  The growth in regular NFT is no slouch either.  IS it possible to effectivly eliminate enough solids through filtration to not clog the emiters with waste?  That would be my main issue.  Also NFT is a wonderful growing style, so i would probably try a small side-by-side test to c if its even worth it to install spray bar emitters.  The growth rates in NFT are much better than growbeds and rival the growth of areoponic ,IMO , with no emitters to worry about (as with aeroponics or your suggested system).  How would you go about cleaning the emitter tube?  How do you currently go about cleaning your nft channels?  I think it is something to look into, but if one thing went wrong with filtration it would be a b**** to clean.  I also would think that if you dont run the pumps 24/7 for the spray emitters, that it would clog.  Giving the h20 time to sit in the tubes unmoved for hours will give the solids plenty of time to settle out.  I like this idea, we will have to see how it evolves over time.

[Kobus Jooste]

The filtration is key, but what I want to do is to run a 20 mm pvc pipe inside a 110 mm one, with a few 2 mm holes drilled in exactly the same position as where the 110 mm has a hole cut for a net pot.  Thus if the holes ever clogged it could be reached by removing the net pot.  The water would originate from a swirl or grid filter, while I will also put inline strainers between the pump and the lines. I do not want to use spray nozzles with fine apertures because of the clogging risk.  The experiment is all about trying to use as little as possible water in these pipes.  What I want to create is a small stream of water that flows down the net pot and roots, thus not allowing the roots to clog the inlets.  Apart from not being able to get a fair distribution of water across all the pots, I think keeping fines out of the water will be the biggest issue.

[Harold Sukhbir]

Hi Kobus,

What a novel and exciting idea!  I like the low-tech approach, can we say, AP sudo-NFT/Aeroponics.? This would be a suitable candidate for the second pump from sump which you are contemplating to commission.To maintain the idea of afford ability, I'm thinking about the use of CPVC here. A very small diameter pipe with sump post filter, holes drilled along top of pipe, placed to one side of net pot which is in NFT pipe. The flow will only be a drip, controlled by simple valve.The pump head should not be an issue for the NFT up top, as this will be just a drip.Any thoughts on this?

[Kobus Jooste]

Not sure which type of pvc I have in mind to be honest - the 110 mm is what we get here as underground drain lines for sewerage and waste water flow from homes, and the 20 mm is electrical conduiting. Here is how I want to set it up: I have a aquaculture design for a overflow outflow from a tank that has been turned into a swirl filter.  I want to modify that slightly to be attached to a standpipe that I fixed into position in the standard gate valve position in the IBR (Centre, bottom) before I buried the IBR in its current position.  By allowing water to flow up this pipe to a small sump situated at the half-way line of the tank, I will be able to place the small sump pump in a box protected by fine screens.  It will pump water to the NFT lines, which will have a second inline filter before the 20 mm pipes are reached.  I plan to have 3 x 5 m pipe lengths as a trial.  There will be three small holes drilled in the 20 mm pipe for each pot position, and I'm hoping that the pump (20 Watt, 1000 liter per hour max) will be able to push water out of the holes in all the pot positions (12 to 16 pots per line) that will wet the pots sufficiently.  The 110 mm pipes will have a uniseal drain in the base to keep as little water inside the pipe as possible. 

 

In the end, I'm hoping to add 2 sets of these (just under 100 plants) either side of my current 4 bed gravel system.  I can then plant less plants in the gravel and hopefully get to use up all the nutrients in my system

[Harold Sukhbir]

Your design is great with the box filtration! It will surely address the suspended fines situation for NFT. However,If you can't produce the head pressure then you may want to consider the drip with small pipe over net pot.I've observed my grid drip pipes on media bed becoming blocked(no pre-filter) but still remain with a slow drip, this is why i never have to clean them as the pea gravel wicks the water throuoght the entire bed so the bacteria gets both air and water , i see no reason why this idea can't be transposed to "aero-drip" to the roots in net pots.

[Kobus Jooste]

Will just have to see how it pans out.  My key objectives is to service as many new plant stations as possible without putting strain on my system's water levels.  I'll also (hopefully) be trying to replace the old main pump with a more efficient one, thus the new system will be using marginally less power than the original even with a second pump.

[Eric Warwick]

Kobus, I have seen this before in hydroponics, and when I asked if the system clogged, they pulled a 3 month basil out, with trouble, and it had a large root mass. They said "yes it does clog". So if you want to keep them there for small plants I see no problem. Since you mentioned how the water will spray, I don't see a problem, with it's intended purpose. I say experiment and tell us how it goes, we want to know.

[Kobus Jooste]

I have finalized the basic design and added a jpeg in this group that is open for discussion - so far no takers on that one.  You are welcome to comment on that one.  I have a 110 mm pipe under passive flow with plants that have been in there for over 6 months, thus I'm hoping that the water source placed where I am going to put it will stay unobstructed.

Eric Warwick said:

Kobus, I have seen this before in hydroponics, and when I asked if the system clogged, they pulled a 3 month basil out, with trouble, and it had a large root mass. They said "yes it does clog". So if you want to keep them there for small plants I see no problem. Since you mentioned how the water will spray, I don't see a problem, with it's intended purpose. I say experiment and tell us how it goes, we want to know.

[Harold Sukhbir]

Hi Kobus,

The NFT in steps are a good idea.My first attempt had this step array also,worked fine!.The reason i suggested the drip in the above post is that I'm concerned about the bio-slime build up in the spry bar. At 90 degrees the pressure will have to be sufficient to get at the plant roots and if it becomes reduced, will slow and be reduced to a drip which will probably not hit the target.If this is happening we have the question of regular  maintenance and as it is an internal pipe may damage roots while having to be removed/inserted.Like all things AP i for one know that we try something and keep tweaking until it works,so go for it!