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My First NFT - Hello, and thanks for looking!

Posted by JVAT none (My Page) on
Thu, Jun 9, 11 at 21:41

Okay, here it is. I have been researching hydroponics for a few years now and pretty intensely for the past 18 months; the wife thinks I have gone insane. I researched, designed and build my very first hydroponic system based on the compilation of information I could find online and in books. I have built a 2 channel NFT system.

So here is the rundown; I used 4”x4”-5’ Vinyl fence posts + caps for the channels. I have them supported on a sturdy folding table about 3’ off of the ground. The design is simple enough. I have a fountain pump supplying nutrient solution out of a 20 gallon Rubbermaid container. The supply line provides a nutrient solution to the upper channel which flows through the first channel before “looping down and around” to the second channel. Solution flows through second channel and “free falls” back into the reservoir. I made the adjustment to the “Free fall” after water levels looked too deep while the initial drain valve was on the terminal end. With the valve removed it looks much more like a film. (The top channel still sits a dit deep (1 cm or more)

I will try to explain as much as I can

60 Gallon Air pump supplies air to the reservoir (via 6” stone) and air to the topside of the two channels (Via small cylindrical air stones). Aeration is augmented by “Vent Holes” in the supply hose from fountain pump (Under the lid of course, the pumps pressure recirculates excess water out of the supply tube which falls right back into the solution) and by the free falling recovery system, I have also read that the free fall method helps vent “exhaust” gasses from within the channels while introducing new oxygen to the solution when it reenters the reservoir.


I have a ¼” drop over the first 5 foot channel, then a 3” step down to the second channel, also on a ¼” slope. I have adjusted my flow to right at 2 liters per minute or just a hair below; Nutrient solution appears to be flowing right around a few millimeters. I have read the slower flow and minimal slope should help increase oxygen and nutrient uptake by the roots.

Lighting is provided by a 2 bulb T8 fixture with Sylvania 32W Octron 6500K bulbs suspended above the system. There is also moderate daylight that comes through the adjacent window. I have made reflective coverings to surround the back, sides and top of the system to retain as much of the (what I understand to be) minimal light as possible. Temperature and humidity are in line with local weather (Northern Virginia) as I have kept the AC off and windows wide open in this room since I started.

So, I started the system with 10 gallons of tap water and ran it for a couple days to check for leaks, check functionality and adjust Ph. Confident that I was mechanically within “industry standards” I added ½ strength nutrients; Dutch Master Grow A & B & Add27 (I came out to 1200 PPM including the taps base of about 350 ppm). I was ready to plant! I started with Rosemary, Thyme and Chive starters. Using a bucket I carefully washed the dirt off the roots of the starter herbs. I placed the root system into my 3” net pots and supported the stems with Expanded Clay Aggregate. A few days later I transplanted a yellow squash that I started from seed and a ‘Patio’ (determinate) variety tomato plant that came as a starter.


That was 3 weeks ago. The system seems to run well and I am pleased with overall mechanical performance but feel like I am really missing out on the plant growth. I have increased the Nutrient solution to 1800 PPM and have not yet changed out the solution. I successfully kept the Ph at 5.8 ��" 6.0 and the PPM count stayed dead on at the original 1200 until I increased the nutrient concentration to 1800 PPM this past weekend. Everything seems as healthy as it can be, there is no wilting, discoloration, drooping etc, but there is no real measurable growth, either. The roots seem to be growing and developing a little length in the nutrient film and a “lung-looking” root system where suspended above the nutrient flow in the chamber. The chives, basil and Thyme stay virtually the same. The tomato shows minimal signs of growth, maybe only a couple of inches in the 2 and a half weeks since transplanting out of the starter pot. Squash continues to grow but nowhere close to as quick as a control subject I transplanted into a compost mix on the same day its Hydro-bound cousin hit the NFT. The Hydro version is less that ¼ of the size as its compost-loving counter-part, but developing. The test squash in compost sits in a sunny window sill.


So now that I have shared a basic picture of the setup I open myself up to critique, criticism and advice. I have many questions and look forward to becoming an active member of your forum.
Initially I would ask…

What’s the deal with transplanting into net pots? I could all but not get the fragile roots through the net pots openings and had to resort to cutting holes large enough to pass them through. I fear that this has bound some of the roots together as the Rosemary and Thyme roots look like soggy ponytails.
Is it acceptable to use only clay aggregate as the substrate or should I be using them in conjunction with something like Coca husk, perlite or Rockwool? (When transplanting from soil starter pot to net pot)

Lighting, is it possible to grow the fruiting vegetables under this light setup? What about the herbs, even if the T8 setup is not sufficient for the Tomato and Squash, shouldn’t the herbs be doing just fine? On that note, is it a disadvantage to be growing different crops at the same time versus growing all of the same type?

Nutrients. Is this “Dutch Master” brand nutrients and additives adequate for these types of crops? I get the feeling that these may be blended for more “controversial” crops and may not be suitable for my hopes of fresh herbs, lettuce and veggies.
Thanks guys and gals!


Follow-Up Postings:

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RE: My First NFT - Hello, and thanks for looking!

When tranplanting, say a plant in a 4-6" rockwoll cube with hanging roots place the roots in then fill in clay pellets. The roots will find their way. You may need to consider the size of the plant and figure if the netpot is the right one for the palnt.

"Is it acceptable to use only clay aggregate as the substrate or should I be using them in conjunction with something like Coca husk, perlite or Rockwool? .

The nutrients that I prefer: General Hydroponics 3-part/CaMg/florashield.


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RE: My First NFT - Hello, and thanks for lookin1g!

Sorry about that. To bad you cant edit ;)

"Is it acceptable to use only clay aggregate as the substrate or should I be using them in conjunction with something like Coca husk, perlite or Rockwool?"

Just the clay is what you want.

BTW Vey nice set up. Try cherry tomatoes in that system.


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RE: My First NFT - Hello, and thanks for looking!

AHHHHHHH!!!! AS TMG stated, the roots need only be covered with the hydroton and they will eventually find their way through the net pots, no need to cut those guys!

I am impressed by the amount of dedication you have put into the system, and it looks like all of the research has payed off! The best part is, you actually made a system that runs well : ) Trust me, now that you have a working system, it will be easy to learn about how the plants grow and what it takes to get them to grow. You need to take into consideration that you will probably be learning about the plants and their needs for about as long as it took you to learn how to make this fantastic system before you are very good at it. Unless you are like Michael Jordan and just know how to play basketball from the get go ; )


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RE: My First NFT - Hello, and thanks for looking!

Yes. Where hydroponics is less leg work it is more brain work. Find the best ppm for your plants. I am sure you know this but the basic macro and micro nutrients and a "cleaner" is all you need to grow.


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RE: My First NFT - Hello, and thanks for looking!

JVAT, I read the post, but was interrupted a few times, so I may have skipped something. Are you planning to move some plants out? That lighting won't likely be enough for larger plants that require lots of light. It's not just important for the health of the plant. It's important for the taste of the fruits. The sugar content of the tomato is largely determined by the amount of light it receives. I ran an experiment and found a real significant difference between using T12 lighting and sunlight when growing cherry tomatoes a couple years back. The kids didn't even like the T12 cherry tomatoes. They couldn't get enough of the ones in sunlight. The herbs will grow, but more light does equal more potency. For example, cilantro isn't nearly as good grown under T12's (never used the T8, but I'm guessing it's going to have similar results). Will they grow? Yeah. Will they be as good? Doubtful. It's like lettuce. I have seen other people post pics of lettuce grown under cfl's and T5/8/12 lighting. They seem satisfied with the results and use it as evidence that you can use this lighting successfully. If I got those results, I'd be adding to the compost bin. I like my leafy greens to be dark green and full of flavor. Never seen any evidence that this can be done under that lighting.

Your plants are awfully close together. Plants get huge when you grow hydro. I would say tomatoes need no less than 24 inches of total space and that is only if you are ready to prune the hell out of them.

How are you planning to trellis? Squash usually needs trellised or staked in the ground. I imagine it is even more necessary in hydro as the plants grow bigger. Obviously, tomatoes need trellising or caged.

I wish you luck. I am not trying to be overly critical. I just hate for you to get too far into it before you realize some of the problems many of us have already experienced.


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RE: My First NFT - Hello, and thanks for looking!

Yea the above poster has really hit alot of points that we left out. In hydro trellesing is huge. Also to fruit yes you will need hps lighting to get a good harvest.


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RE: My First NFT - Hello, and thanks for looking!

  • Posted by JVAT none (My Page) on
    Mon, Jun 13, 11 at 14:22

Thanks for all of the positive feedback! I build the system with 12 net pot holes but already have figured that I may need to keep some of them empty as adjacent plant size dictates. As far a trellesing I plan on "training" the tomato and Squash to twine running from the ceiling, securing the vine every 12" or so then using zip-ties or something to that effect for supporting the fruit/veggie clusters as needed. Thanks for all of the positive feedback so far! I build the system with 12 net pot holes but already have figured that I may need to keep some of them closed-off as adjacent plant size dictates. As far a trellesing I plan on "training"
As far as herbs, assuming I get any substantial growth, I am going to keep the herbs pruned (the wife and I cook from scratch regularly and use fresh herbs with most meals.
Ideally, I would like to have the squash, the �patio� tomato and the herbs, and then if things are going okay, adding lettuce (or other greens) as space permits.
@joe.jr. No, you didn�t miss anything, right now, the 2 bulb T8 fixture is all I have. My plans are to purchase a HID light setup within the next week. I spent MANY hours researching pros and cons of the different varieties available. Once I have the HID setup, I will use the T8s for seed germination in rockwool.
So on the HID light topic� I like the specs on a few 400W models that I have found. 400W should be adequate for my 4.5�x2� area, correct? I don�t want to overkill it as overall space and monthly power bills are a part of my equation. I have seen 400W "Light Kits" that include Electronic Ballast, reflective hood, HSP and MH bulbs. The claims are that the ballast and hood can run/fit/hold either bulb type. Is there any validity to these claims? Are there any drawbacks to one of these "combination" HSP/MH kits?

Here is a link that might be useful: 400 Watt HPS/MH combo


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RE: My First NFT - Hello, and thanks for looking!

Just wanted to add that fruiting plants can be grown successfully as well as tasty with florescent lighting, provided they get enough light. However I don't think it's really any more cost effective than using HID lighting. But here are a few videos of a hydroponic grower that has been using nothing but florescent lights for years to grow everything from peas, to beans, to tomato's, to berry's, to melons, to pineapple etc.. And even just regular flowers too. Also, from what he said in another forum, the fruits and veggies were very tasty as well.

insert anchor text
grow room update
Growing floral flowers with hydroponics
the light setup
overgrown grow room
tons of tomato's, peas, and melons
overgrown grow room 2


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RE: My First NFT - Hello, and thanks for looking!

  • Posted by JVAT none (My Page) on
    Fri, Jun 17, 11 at 11:27

@homehydro - Some of those are pretty cool!

Last night I acquired HID lighting. Hydrafarm 400W MH setup and a Generic 1000W HPS setup. I Installed the 400W last night, tested it, checked for safety and rigged a box fan for temporary heat reduction. Today is day 1 with the new light, Im pretty excited to see the difference.

The 1000 W may be overkill for my limited space but I figure I can run it intermittently (2 on 2 off or something to that effect, any advise appreciated!)when my veggies really get going.


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RE: My First NFT - Hello, and thanks for looking!

Not sure what you mean by 2 on 2 off. Do you mean hours? I recommend against that if you do.


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RE: My First NFT - Hello, and thanks for looking!

  • Posted by JVAT none (My Page) on
    Sun, Jun 19, 11 at 3:30

Yes, I am wondering if it would make overall sense to run the 400w MH for say 12 hours a day (or whatever timelegnth, 14 or 15 hrs) and then in order to conserve energy costs, only run the 1000w HPS intermittently, 2 hours on 2 hours off, or 3 and 3. something to that effect. Or does the light need to fall for a consecutive amount of time, say 6 hours straight.

Because I am attempting to grow multiple plant types simultaneously, I would like to provide both light sources daily. I have so much to learn!


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RE: My First NFT - Hello, and thanks for looking!

You could, if you have the means, run the MH light with fluorescent as the supplementary lighting. Then switch to HPS for flowering and continue to use the fluorescent as supplementary. If you could put the fluorescents lower and on edge to shine from the sides, that would increase the amount of light lower than the canopy without the increase of heat from the HPS.

Also, I misunderstood. I thought you were going to run the HPS and MH alternatively, like the HPS 2 hours and the MH the next 2 hours. It is my understanding that turning the light on is harder on the bulb than leaving it going and the more often it is turned on and off the shorter the life. I have no evidence of this. I've only heard that is the case. Something worth at least looking into.


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