Download - DIY Outdoor NFT Hydroponics System

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DIY Outdoor NFT Hydroponics System

by djm02f

Hello friends. I am going to share with you my homemade NFT (Nutrient Film Technique) outdoor hydroponics system. Ihad wanted to start a hydroponics project for some time, and after a bit of research, I decided to go with an NFT systembecause it has several important features. As explained by epic gardening.com, its myriad bene ts include:

Low water and nutrient consumptionAvoids need to use a lot of growing mediaEasy to disinfect roots and setupEasy to see root quality and healthConsistent ow prevents salt buildup in root areaRecirculating, so minimal groundwater contaminationVery modular and expandable

It's few dowsides are:

A failing pump can kill an entire crop within a few hoursDoes not work well with plants that have large tap-root systemsDoesn’t do too well with plants that need a lot of support

Since I was interested in growing lettuce and other salad greens, which need little support and have small root systems,two of the three detrimental factors were moot, and long power outages are few and far between, so a failing pumphopefully will not be an issue.

The entire system was up and running in less than a week (only a few days worth of work) and cost me less than $200,and everything can be a ordably sourced from either your big box hardware stores (namely Home Depot and Lowes) oryour online everything vendor (Amazon and Ebay). It is modular, meaning you can add or subtract rows of pipe or lengthfrom each row, so as to tailor it to suit your own needs. So without further ado, lets get to it.Supplies:

There are a lot of supplies to be purchased, but don't be daunted: all can be purchased for a total of about 200 bucksbetween Ebay, Amazon, and your local big box hardware store.

There are two main parts to this project: the frame, and the plumbing. For the frame, which measures 50 1/2" in height(without the caster wheels or manifold), 60" in length, and 48" in width, the materials you will need include:

Frame:Frame:

Lumber:

2x4s: 22'

1x1s: 20'

DIY Outdoor NFT Hydroponics System:

http://www.instructables.com

http://www.instructables.com/DIY-Outdoor-NFT-Hydroponics-System/

http://www.instructables.com/member/djm02f/

https://www.epicgardening.com/nutrient-film-technique/

2x6s: 22'

Screws:

1 box of 2" 9 ga. for most of the connections, 1 box of 1&1/4" to screw the 4 horizontal 1x4 " anges" to the 1x1 "webs" ofthe "T" beams. I used Deckmate exterior screws, which are coated to inhibit corrosion.

Corner braces and corner brackets:

Since the system depends on a rather speci c slope from one end to the other, I braced all of the 90-degree angles that Icould using brackets and braces to prevent sagging over time.

Caster wheels:

I used 4" caster wheels with a threaded stem. These were then mounted onto corner brackets, which were in turnmounted onto the frame.

Paint:

Used to help protect the lumber from the weather, as well as for aesthetics. You have some discretion here, but(assuming the system is set up outdoors) an outdoor paint is advised.

Plumbing:Plumbing:

Hydroponic Channels: 20' of 4" "Sewer Main" PVC (cheaper than standard "Schedule 40" PVC, the only di erence (to myknowledge) is that it has a thinner wall than Schedule 40, and thus is not meant for pressurized applications. As this willbe an "open system" (which does not operate under pressure), this should not be an issue.

Return manifold

10' of 2" PVC for the return manifold and return pipe (which ows back into the reservoir)

2 X 2" 45 degree elbow joint

3 X 2" 45 degree wye joints

3 X 2" 90 degree elbow joints

4 X 4" PVC exible pipe caps

4 X 3/4" slip x slip bulkhead ttings

2" stainless steel pipe straps

Intake manifold

1 X 4-way garden-hose manifold (this should have a shuto valve for each output, allowing you to select which channelsreceive water at any given time)

1 X 3/4" brass hose barb x GHT (Garden Hose Thread) tting: mine is "male" thread (MGHT), but this may need to befemale (FGHT) depending on which manifold you go with

4 X 1/2" brass hose barb tting x FGHT

4 X brass dishwasher elbows (they have FGHT on one end, and a 90 degree elbow on the other)

1 X 10' length of 3/4" ID corrugated tubing (black): it should be black to prevent light from penetrating it, but will bepainted white to keep it cool

1 X 5' length of 1/2" ID tubing (black)


Step 1: Draw Out You Plans

Buy yourself some graph paper and make some drawings. It is much easier to have a separate page for each element withyou outside (or in your workshop, etc.) than to be scrolling through a laptop. It is also advantageous to have a welldetailed plan that you have made yourself, so that you will better be able to envision each piece and how they ttogether.

Label each length of lumber with a circled letter {(A), (B), (C), ... etc. A few of these dimensions will be used for more thanone (interchangeable) piece, so use the same letter for each identical piece. Make a list including each piece,consolidating like pieces [for example, you will want 6 horizontal 2x4s of 24", so if you label these pieces (A) on yourdrawing, your list will have: (A)-2x4 24" x 6]. Then you will know how many of each length you will need to cut.


Step 2: Gather Your Supplies

While the stu that you have to order o of the internet will take a few days to arrive, you can get started with some ofthe elements of your system at your friendly local hardware store. I found the quality and price of lumber to be better atHD, while the PVC was cheaper at Lowes.

In order to best economize your lumber and reduce waste, you want to make cuts so as to either have enough left overfor another piece that will be used, or have as little left over as possible. For example, for the lumber for the back verticalsupports you will need 3 lengths of 2x4, one each of 46, 47, and 48 inches; this can all come from one 12 foot length, withonly 3 inches left over as waste.

So for lumber, you will need:

2x4 x 12' (3 back vertical supports)

2x4 x 12' (6 horizontal supports)

2x4 x 12' (3 front vertical supports and 1 back horizontal support)

2x6 x 10' (3 diagonal supports)


Step 3: Cut Your Lumber/paint Your Wood

Most of the cutting is pretty straight-forward: the only somewhat-tricky part is cutting the notches for the horizontalpipe supports into the diagonal cross-bars. Use your saw of choice; I used my dad's adjustable miter saw. It is pretty muchjust a circular saw mounted inside a fancy frame which allows for cuts at precision angles.

Remember, the frame is meant to slope down from the intake to the out ow side, so all of the measurements for yourvertical supports should re ect this slope of about 30:1 (30 horizontal inches for every inch of drop). Since my frame is 60inches (or 5 feet) long, this gives us a nice even drop of two inches across the entire length. And since the second set of


Step 4: Assemble Each Section

vertical supports is set halfway across, or 30 inches, this section will be exactly one inch lower than the rst section at theintake side.

As for those tricky diagonal pieces, double and triple check the angles on the notches you'll be cutting out. Remember,these 2x6's will be at a 45 degree angle, so the notches cut out will likewise feature a right (90 degree) angle cut into thewood, and two 45 degree angles (or, rather, 135 degree angles), one at each corner leading to the 90 degree cut. Ihonestly can't remember the math or tools I used other than a T-square (since this is being written several months afterthe project's completion), but it's nothing too complex.

Plan your cuts ahead so as to best economize your lumber (leaving as little unusable length as possible), and sand downany rough edges after all your cuts are made. After all of your cuts are complete and you've nished (sanded) all therough edges, you'll be ready to paint.

Painting is done for two purposes: to protect your lumber from the elements (assuming this apparatus will be spendingits days outdoors), and for aesthetic concerns. My folks already had a theme going with all of their other backyard lumberprojects (a couple pergolas and a fancy planting shelf ) painted the same tone of red, so my choice was pretty muchmade for me. We had plenty of the blood-red paint left over, and since it was outdoor-rated, I was good to go. Two coatsfor better protection, took a good few hours (given the many pieces that needed doing), and it was done.

There are three of these diagonal support sections that need to be put together. Keep in mind, the second section shouldbe one inch shorter than the rst, with the third section two inches shorter than the rst. Therefore, the upper horizontal2x4 of the rectangular section will need to be 1 and 2 inches lower on the second and third section, respectively.

I used a Kreg mini jig for drilling "pocket holes," which conceals the connecting screws quite nicely, giving the nalproduct a very professional and nished look. You can get the Kreg mini jig kit for 14 bucks on Amazon, and I'd highlyrecommend it. If you do decide to go with the Kreg, I'd suggest that you do one or two practice holes on a couple piecesof scrap wood, just to get the process down.


First do a "dry tting," making sure all of your dimensions are right on. Then, using clamps, screw the bottom horizontalpiece onto the (long) back vertical piece. Next, place the (short) front vertical piece onto the bottom horizontal beam,and screw it on in. Then do the top horizontal piece. You should now have a rectangle, with one end extending a couplefeet in one direction out from the rectangle. Clamp the diagonal piece in place, and screw into the rectangle and theboard extending from it. You should now have your rst section complete.

Do the same with the other two sections, keeping in mind that they ought to be one and two inches shorter (in thevertical dimension). You should now have three nearly identical pieces (the only di erence being that the second andthird are one and two inches shorter, respectively).


Step 5: Make Your "I" Beams

These are fairly simple. All you are doing is taking a (painted) 1x4 and attaching a couple of sections of 2x2 or similarlumber along the length of the underside. You must do this in a couple sections because you want the bottom of the 1x4

ush against the vertical supports (so the 2x2 of the "I" beam runs between the vertical sections. Mark your 1x4 wherethe 2x2s will start and stop: you need to leave a couple inches "bare" where the 1x4 will rest directly on the verticalsections. Then cut your 2x2s to length, paint them, let them dry, and clamp them along the length of the 1x4s. You wantto drill a pilot hole through the 1x4 into the 2x2 (preferably without coming out the back end), and then screw throughthe 1x4 into the 2x2. Use outdoor screws (I like deckmate screws, which are coated to inhibit corrosion).


Step 6: Put the Frame Together

Once you have your 4 lengths of 1x4 I beam complete, compare to make sure that the I beam sections are all bare in thesame spots. These spots are where the 1x4s will drill directly into the vertical supports.

Now your frame will really start coming together. Stand up each of your three sections the appropriate distance apart;DIY Outdoor NFT Hydroponics System:

Step 7: Prepare Your Channels (pvc Pipe)

you will likely need to lean the three vertical sections against something to keep them upright (at rst). Put your four 1x4I beams into position, and drill drill drill. Make sure you use the appropriate vertical section in each place, so that it slopesslightly from one side to the other. Next, attach the horizontal 2x4s between each section

Build a couple rectangular frames for the doors out of 2x2 lumber (they actually won't be perfect rectangles, as one sidewill be slightly shorter than the other, to match the slope of the frame). Then a x shade cloth to the doors with "shadecloth staples" (don't cheap out and use regular staples: shade cloth staples are hammered in and attach the shade clothmore securely).

Now you will want to attach shade cloth around the bottom "box" section of the frame. This will help keep the reservoirshaded and cool (which is essential to prevent root rot), as well as allowing you to store supplies within mostly concealed(so there is an aesthetic component as well). A light colored shade cloth re ects most of the light (and heat), but allowsthe reservoir to stay somewhat ventilated (i.e. it won't "hot box" the rez, as a closed wooden frame would).

You can now attach the doors to the frame with hinges of your choice, just don't go with anything too imsy. A coupledoor catches (pinch style or magnetic will work) will keep the doors from swinging open unexpectedly.

Now: caster wheels. This step is optional, but I found it a great convenience (both for moving the frame out todrain/clean the reservoir, and for wheeling the whole frame against the inside corner of the house last time a hurricanecame 'round). I bought non-marring caster wheels (so they wouldn't mark up the ground) that have an integral threadedstem. Then, bought some stainless nuts with the same thread/diameter. I then drilled holes the diameter of the threadedstem in some stainless corner braces, and attached the corner braces in the places that I wanted the six wheels. Finally, Iscrewed one nut onto the stem, fed the stem through the hole in the corner brace, and sandwiched (backed) the twonuts tightly against each side of the corner bracket, thus securing the caster wheels in place.

Now you can go ahead and cut your 4 inch pvc pipe to length. I cut mine so that it extends just about 2 inches o theback (collection) end, and is almost ush with the distribution end (extending just about half an inch). Now you'll want tobreak out the hole saw bit and drill the holes for the net pots: I drilled the holes on 6 inch centers (the center of each hole6 inches apart). I also staggered them, so that the holes of the top channel alternate with those of the channel below (the

rst and third pipe have the rst hole 5 inches from the end of the intake side of the channel, the second and fourth havethe rst hole 8 inches in). This leaves room for the intake, which is a dishwasher elbow with a female thread connected toa brass nipple with a male thread.

When sourcing your brass (or plastic, etc. pieces: I found brass best, most cost e ective, and easiest to source), make surethe thread is the same on the male and female pieces. I went with garden hose thread, which will be abbreviated eithermght (male garden hose thread) or fght. The nipples I used are 1/2 inch/fght, meaning it has a nipple to accept 1/2 inchhose on one end, and female garden hose thread on the other. To install, just feed each piece through their respectiveends of the 1 inch hole you've drilled, and sandwich the pipe between them and screw together. The dishwasher elbowshould be pointed down the long end of the pipe.

Now get some rubber DWV pipe caps. Drill a 1 1/2 inch hole for the bulkhead ttings near the perimeter of the at end,about 1/4 inch from the edge. Now sandwich the bulkhead ttings around the hole (after you've glued your corrugatedpond tubing into the end of the bulkhead tting with silicone caulking [the corrugated tubing is less likely to kink withthe sharp 90 degree bend]). You may also want to paint the end caps/tubing white, to keep them cooler in the sunshine,thus preventing your nutrient solution from taking on heat. Make sure you leave enough corrugated tubing length tofeed into the drainage manifold, which you will now assemble.


Step 8: Drainage Manifold

The drainage manifold collects the nutrient solution from the channels and feeds it back to the reservoir. All of thefollowing pieces will be in 2 inch PVC. You will need 1x 45 degree elbow tting, 3x 45 degree wye ttings, 4x end caps,and 3x 90 degree elbows. 10 feet of 2 inch pvc should do it. First, cut some 4 inch sections of pipe to attach the end capsto the top end of the 45 degree and wye ttings (note that the bottom wye tting will be inverted from the other two, sothat it accepts the pipe in line with the others, but drains 90 degrees from the ground - this means that the end cap willbe placed di erently from the other two wyes. Next, prep the surfaces of the ttings/pipe that will be glued with a very

ne grit sand paper. Now use some PVC cement to glue the pipe into the wye, and then the cap onto the pipe thatextends from the wye. You can drill a hole into the middle of the cap now to accept the corrugated tubing from thechannels.

Now you will cut the pipe that runs between the top 45 degree elbow and wyes. Remember, measure twice, cut once:you want each drainage cap to be located as close to directly under each channel as possible (about 2-3 inches under,actually, so that you can bend the corrugated tubing a bit more gradually). Sand and glue each section in, making surethat they are all in line in regards to the channels. Again, the bottom wye is inverted so that it drains straight down.

Connected to the bottom wye is a 90 degree tting that directs the pipe towards the back of the system, then another 90degree elbow that directs the pipe towards the intake manifold end, where the reservoir will sit. Finally, one more elbow(with a short length of 2 inch pipe glued into it) will direct the ow downward into a hole drilled into the top of thereservoir. Run the pipe close to the wooden frame, so that you can use 2 inch pipe straps to support the pipe. You willalso use these pipe straps (make sure that they are made of stainless or some other non corroding material) to secure themanifold to the side of the frame (which means that the manifold will be right against the frame: so you cannot have theoutput end of the channels extend past the frame at all).


Step 9: Shade Cloth Awning (Update)

So, after about one year of mostly successful operation (and some mighty good lettuces), I found that, during the warmermonths, my lettuces would wilt, usually during early to mid-afternoon (when the sun/heat were strongest): the larger theplant, the more prone to wilting. I rst combated this by leaving the seedlings in the DWC system a bit longer, allowing amore robust root system to develop (which helped somewhat), but even this was not enough for the Florida heat. Finally,I got up and did what needed to be done, building a retractable shade cloth awning.

First, I added 4 new lengths of 2 x 4: two along the rear vertical 2 x 4's of the frame, and two extending about 4 inchesfrom the rear horizontal support. I then added a long 1 x 4 to each of the two rear vertical 2 x 4's (this is to support thetop/rear end of the shade cloth. To the horizontal 2 x 4 extensions, I added a small strip of 1 x 4, upon which I mountedpillow block bearings (easily sourced o Ebay for about 10 bucks each)

The bolt that mounts through the pillow block bearing goes through another length of 1 x 4, so that this length canswing from a vertical position freely down to a diagonal position.

Then, at the high end of each of the four lengths of 1 x 4, I have a bolt, secured with a nut, which extends into a piece of 1inch pvc pipe. I sewed the shade cloth in a loop at the end (using weather resistant polyester thread), through which I fedthe pvc pipe, which extends the length of the hydroponic system and terminates at the bolts through the 1 x 4'sdescribed above.

Voila: during the warmer months, I can leave the shade cloth awning extended, providing some much needed relief formy lettuces. And in the cooler months, when I want to maximize the amount of sun shining on my crop, I can swing upthe diagonal arms of the awning and roll up the shade cloth. So far, so good: no more wilting in the mid-day heat.


Great job!!

Thanks!

This setup looks great :)

Thanks, Penolopy!

Great job !One question : is there a specific reason why your four « lines » are in parallel while manysystems run one big line with all the gutters in serie ?

Thanks Jacques-Olivier. Yes, two reasons: first, I found it simpler to have all channels slope inone direction; all I had to do was build the second vertical support one inch lower than the first,and the third two inches lower. Otherwise, I'd need a rather complex back-and-forth system whichcould, theoretically, be achieved by cutting shallower or deeper into the diagonal 2 x 6s, but thedeeper cuts would leave it less structurally sound. It does, however, necessitate a collectionmanifold (as opposed to one simple drain), which is rather easily built, but does take someplanning. Secondly, if they were all in one long series, the plants near the end of the series wouldget less water/nutrient than those near the start, and I'd need to increase flow to compensate(which could, in turn, necessitate larger bulkhead fittings to drain, as well as resulting in unevengrowth along the system); it also turns out that increased flow rate can decrease nutrient uptake,according to my research. Thanks for the question.

Step 10: Grow Some Veggies

Your system is done, congrats! Now to grow some veggies. I start my seeds in rockwool cubes; once they've sprouted, Imove them into a grow box with a mini DWC (deep water culture) system with LED lighting (soon to be the subject ofanother Instructable), which allows the roots to grow out into the nutrient solution/water. I also inoculate the roots witha mix of mycorrhizial (bene cial) fungi and bacteria (bought either online or at your local hydroponics supply store), tohelp keep them white and healthy (generally you need to keep the solution under 80 degrees F, but with mycorrhzae,you can push that up a few degrees without encountering root rot). Once there is enough root growth to reach thebottom of the NFT channels, I transfer them into the outdoor NFT system. If you do not feel like building a grow box, youcan try an outdoor mini DWC system, ambient temperature permitting.

Well, there you are. I hope this how-to will help to inspire/instruct some of you to try your hand at home hydroponicgardening, which can be a fun, healthy, economical, and environmentally friendly pursuit. Any feedback is muchappreciated. Cheers, and happy gardening!


Download - DIY Outdoor NFT Hydroponics System

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