Thoughts on Hybrid NFT system.

I am looking at a small commercial facility in Oklahoma. We have the existing building and have a space 16'x24' to use as a flower room. This will be a temporary location until we can get a new building up and operating. Do to the space restrictions we are trying to maximize it. I am wanting to use the below system to flower plants in. We will have 8 of the tables. 32"x 16' ea. We will be doing a Sog style. We will be operating in a total sealed space, temp and humidity controlled. We plan on CO2. We will have 20 1200w LEDs covering the 16'x20 grow area.

My main concern is the water in the pipes prior to it returning to the holding tank. The 4" to 6" reducer on the end of the drain side will cause a 2" water level in the pipe. with the slope it will be 2" at one end and 1/2" at the other. Will the water stagnate with a constant flow from the pumps? Will I have root issues with this amount of water in the pipe?

The picture is a sketch of the piping without the stands that hold it up. Please use a little imagination.

Second question, Because we plan on using these in both veg and flower they are on wheels to move from one room to the other. In veg the plants roots will be a couple of inches above the water. I plan on adding a wick during veg to get the water from the bottom of the pipe up into the pot. I am expecting by week 2 of veg the roots will have found the water. Has anyone tried combining NFT and Wick together? What should I be careful of?

Any thoughts on this system would be helpful. Thanks,

JoelK said:

I am looking at a small commercial facility in Oklahoma. We have the existing building and have a space 16'x24' to use as a flower room. This will be a temporary location until we can get a new building up and operating. Do to the space restrictions we are trying to maximize it. I am wanting to use the below system to flower plants in. We will have 8 of the tables. 32"x 16' ea. We will be doing a Sog style. We will be operating in a total sealed space, temp and humidity controlled. We plan on CO2. We will have 20 1200w LEDs covering the 16'x20 grow area.

My main concern is the water in the pipes prior to it returning to the holding tank. The 4" to 6" reducer on the end of the drain side will cause a 2" water level in the pipe. with the slope it will be 2" at one end and 1/2" at the other. Will the water stagnate with a constant flow from the pumps? Will I have root issues with this amount of water in the pipe?

The picture is a sketch of the piping without the stands that hold it up. Please use a little imagination.

Second question, Because we plan on using these in both veg and flower they are on wheels to move from one room to the other. In veg the plants roots will be a couple of inches above the water. I plan on adding a wick during veg to get the water from the bottom of the pipe up into the pot. I am expecting by week 2 of veg the roots will have found the water. Has anyone tried combining NFT and Wick together? What should I be careful of?

Any thoughts on this system would be helpful. Thanks,

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I would just use a 6" elbow and reduce afterwards. Problem solved.

@JoelK is that going to work for Ya? Or did you just disappear?

I think i need to clarify. I am looking to see if anyone has used a NFT system that had a small dam on the tube to raise the water level a small bit. Is this beneficial or will this cause root rot. Deep water systems have the roots under water all the time with no issues, but this will only have a very little under water all the time, along with a wick, the roots should get water and nurts in smaller amounts all the time. The 6 to 4 reducer is to build the dam. My thought is that if a pump fails, the small amount of water in the tube that is dammed up will act as a buffer and keep the root system from drying out before we can replace it. Is this a plausible theory? Thanks,

As a safety feature in case of pump failure, it will certainly help. Over all, I dont think it will matter much as far as how well the plants do. All forms of hydro seem to work very well for the people who keep the temps/PH/nutes within the proper ranges.

If you want to get pedantic or nit picky, having that pocket of water takes away, to a small degree, the main benefit of doing NFT - the thin film part. On the other hand, almost no one actually does NFT properly. Most do a Nutrient "Flood" rather than a thin "film" by running pumps that pump way to much water flow. A flood is not the same thing as a thin film.

Yeah, I wouldn't want the "dam" if it were my setup. Build it with a 6" 90*.

"On the other hand, almost no one actually does NFT properly. Most do a Nutrient "Flood" rather than a thin "film" by running pumps that pump way to much water flow. A flood is not the same thing as a thin film."

Larry3215, what is the benifit or downside to running more flow vs thin flow? I really did not know where was a difference. In the set up i am planning there will be 14 plants in each 16' long 6" tube.

Airwalker16, do you have any idea how long it takes the roots to dryout if flow stops in a NFT system. It could be up to 12 hours between a night and 1st day inspection.

JoelK said:

"On the other hand, almost no one actually does NFT properly. Most do a Nutrient "Flood" rather than a thin "film" by running pumps that pump way to much water flow. A flood is not the same thing as a thin film."

Larry3215, what is the benifit or downside to running more flow vs thin flow? I really did not know where was a difference. In the set up i am planning there will be 14 plants in each 16' long 6" tube.

Airwalker16, do you have any idea how long it takes the roots to dryout if flow stops in a NFT system. It could be up to 12 hours between a night and 1st day inspection.

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I see what you're saying. I would be worried too I suppose .maybe you could figure out some kind of mechanism to trigger a second pump if the first one dies. But honestly, don't over think it. The pools will be fine, just not a true NFT. Use the 6" elbow if you want it to flow evenly and work like its supposed to.

Another option is to use a very thin mat of coco fibre or rock wool along the bottoms of each pipe, so they stay wet in case it did happen and pumps failed. Coco fibre actually now that I've thought of it is a really fucking great idea.....

Build it like I suggested so it flows with no pooling or obstruction and use coco fibre along the length of each of the 3 pipes. It's also a great way to help give your roots something to hold on to. They'll get heavy during the end of flowering. I better see some pictures. All I can say is that if I was having this problem, this is what I would do, hands down.

JoelK said:

"On the other hand, almost no one actually does NFT properly. Most do a Nutrient "Flood" rather than a thin "film" by running pumps that pump way to much water flow. A flood is not the same thing as a thin film."

Larry3215, what is the benifit or downside to running more flow vs thin flow? I really did not know where was a difference. In the set up i am planning there will be 14 plants in each 16' long 6" tube.

Airwalker16, do you have any idea how long it takes the roots to dryout if flow stops in a NFT system. It could be up to 12 hours between a night and 1st day inspection.

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Thin layers of water work better at getting O2 and nutes to the plants. A very thin layer of water will reach 100% DO almost instantly, and can stay at 100% DO while feeding that O2 to the roots. A thin layer can replenish the O2 as fast as the plant uses it up. That will keep the roots supplied with O2 better than a thick layer. O2 dissolves and disperses through water fairly slowly, so if you have a thick layer of water, the water right up against the roots will drop in DO as the plant uses it up while the outer part of the water stays as a higher O2 level.

NASA did some research a while back and found that water droplets in the 20 - 50 micron size were the ideal size to feed plants O2 and nutes, and have them grow the fastest. Thats why hi-pressure aero/fog-ponics work so well - the droplet size is really small and the water can stay at 100 DO at all times.

You dont want to go too small or too large though. Too small a droplet size makes for "dry" fog and the roots cant get enough water.

Even true NFT cant get a layer that thin, but less is more when it comes to water/air ratio and roots - as long as they dont dry out. This is also why the Membrane Meniscus method is supposed to be so much better.

The "perfect" hydro system would supply water exactly as fast as the plant used it up, but only as a very thin layer or in 20-50 micro droplets. Not the easiest thing to do in the real world.

I have never tried coco fiber. Will it stay in place? Not break up and get into the res. Fouling the pump? Also how long does it last. I am going to make this a production system, every 8 to 10 weeks, it needs taken down and cleaned. Then recycled to a new batch. Can coco be reused or is it disposable?

Larry3215,
Thats a lot of good info.
It sounds like aeroponics is the best way to feed the roots. Im not sure i want to attempt trying it yet. I know I'm not that experienced yet. If I won't be doing any harm to the roots with a NFT system, then I'll keep heading down this path.

If anyone can see a reason this wont work please let me know. Thanks.

JoelK said:

I have never tried coco fiber. Will it stay in place? Not break up and get into the res. Fouling the pump? Also how long does it last. I am going to make this a production system, every 8 to 10 weeks, it needs taken down and cleaned. Then recycled to a new batch. Can coco be reused or is it disposable?

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It's literally perfect for this situation man. And make sure to always, coco fiber or not, use a mesh filter bag on your pump to keep things filtered. It's by far the easiest way to have only clean water running through your pump and is so incredibly simple to clean. It's a bag with a draw string...

https://www.amazon.com/CoirPlus-Premium-Coco-Grow-Listed/dp/B015AICO6Y/ref=mp_s_a_1_11?ie=UTF8&qid=1532925505&sr=8-11&pi=AC_SX236_SY340_QL65&keywords=coco+mat+hydroponics

https://www.amazon.com/Biostrate-Hydroponic-Growing-Mats-Biodegradable/dp/B01523IXLM/ref=mp_s_a_1_3?ie=UTF8&qid=1532925681&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=coir+mat+hydroponics&dpPl=1&dpID=41+ZU7komnL&ref=plSrch

I think the second link is a much better deal and more of what you'd want to use.

But if you wanted to search yourself, it's called Coir Mat, Coco Fiber mat hydroponics, coir fibre. Any of those or combination of them will yield you results in a Google Search.

that makes perfect sense. Use a filter bag on the drain back. That stops anything.

Thanks, great suggestion. I'll look up the coco products and see if i can get a sample.

I'd put the filter bag around the actual pump itself if it were me. But you can do as you please.

I have my pump rigged outside the rez to reduce heat build up.

I take a piece of 3/4 PVC pipe about 18" long, and drill a bunch of 1/4" holes in it. Then wrap it in silk screen cloth with some zip ties to hold it in place. That is used to filter the water before it goes into the pump. I have a thru fitting from the rez to the pump and that pipe/filter attaches to that fitting inside the rez. Its just a slip fit so I can pop it off to clean the fabric.

Larry3215 said:

I have my pump rigged outside the rez to reduce heat build up.

I take a piece of 3/4 PVC pipe about 18" long, and drill a bunch of 1/4" holes in it. Then wrap it in silk screen cloth with some zip ties to hold it in place. That is used to filter the water before it goes into the pump. I have a thru fitting from the rez to the pump and that pipe/filter attaches to that fitting inside the rez. Its just a slip fit so I can pop it off to clean the fabric.

Click to expand...

That's very smart.

I like that idea also. It will not add heat to the water. What pump are you using. I had planned on submersible style.

Im using the EcoPlus pumps. I have two of the Eco396 pumps. They are easily converted from submersible to in-line. They even come with the necessary barb fitting to go back and forth. Takes about 1 minute to convert one.

https://www.amazon.com/gp/product/B0018X2XT4/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

I've grown in tubes with only a 5mm thick foam piece to secure the plants in the holes... If your pump pushes well enough the water level is sufficiently high to get where it needs to without damming anything up. I don't think you will have issues with oxygen with constant flow, but it might be loud as all fuck.