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Picture of Small NFT Hydroponics System
Hydroponics is a type of agriculture that uses no dirt, and usually results in larger, fuller plants. I recently became interested in the topic, and decided to start my own vegetable garden using the Nutrient Film Technique (NFT). It involves a channel of nutrient enriched water constantly flowing past a plant's roots. The system that I'm demonstrating here is just one example of infinitely many possibilities. Take my work and use it as inspiration for developing a system that suits you and your needs.
 
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Step 1: The Idea

Because hydroponics requires a resevoir for water to be drawn from and returned to simultaneously, and I was just building a small system, my design has two gullies. This allows the water to easily go full circle.

Along with the water pump, my system uses gravity to assist the flow of water. Each end of the PVC is one inch higher than the end that comes next in the circle. The end of the tube that water enters from is the highest, and the end that it leaves from is the lowest. To achieve this, I built supports out of lumber for the pipes. The supports also keep them high enough to be above the reservoir, so that gravity will return the water to it.

Step 2: Materials

Picture of Materials
  • 66" of 4" PVC Pipe - If I didn't already have PVC, I would have probably bought plastic gutters.
  • Assorted lumber - Go to the cull wood section of your hardware store. This is the wood they cut for other people who didn't want the scraps. I got four 43" 2x4"s, one 1.5x7.5x58" piece, and a scrap of plywood for $3.
  • Screws and such
  • 4 rubber adjustable end caps with hose clamps - about $3 each
  • Submersible pump - I'm using this
  • Teflon tape
  • 16 oz Plastic cups
  • Plants
  • Irrigation tubing
  • Opaque Bucket
  • Plumbing cement
  • Growing medium - I used expanded clay ball
  • Hydroponics Nutrient

I would make a list of tools, but there's no way I could make an exhaustive list.

Step 3: Build the stands

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Once you figure out the height of your reservoir, you can start designing your stands. Mine is about 13" tall, so my stands are 13", 14", 15", and 16". After cutting the lengths, I cut a triangle (with a height of 2.5") out of each one to hold the PVC.

I'll assume you've already cut the PVC in half...it doesn't really deserve it's own step.

Next, I attached them together with the 2x4's. I found out the hard way that it's easier to make them level if you attach the 2x4's mid way up, instead of at the bottom.

Step 4: Plumbing

You'll need to drill a hole with a spade bit suitable for your tubing in each of the end caps. Drill the holes at the height that you want your water level to be at. I didn't think about it at first, so you'll see in the pictures that they're at the edge, I later had to adjust this, but there's a picture of that, too. Make sure your water level is high enough that the bottom of your cups will be submerged.

My pump came with a removable attachment for the tubing, so I wrapped one side of it with Teflon tape and used plumbing cement to attach it to a piece of tubing long enough to reach from the upper tube to the bottom of the reservoir. I then pushed the tube through an end cap's hole. Push another piece long enough to reach from the lower tube to the reservoir. Then attach two end caps via tubing long enough to fit on both pieces of PVC.

When I tested the system like this, it ran surprisingly well, with a just a few small leaks. Use the plumbing cement to seal around the outside of all the tubes. Plumbing cement isn't the most safe substance (toxicity wise), and even though it's probably OK, by just sealing the outside, it at least makes me feel better about. Luckily this stuff cures in two hours, so you can do another test run pretty quickly.

A lot of people recommend cleaning everything with a heavily diluted bleach solution to help ward off algae. I did this before I had drilled any holes. It was easy to fill the pipes and then shake them with the end caps on.

Step 5: Holes

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Depending on your plants, the spacing of your holes will be different. I wanted to plant at least six plants, so my spacing worked out to be 8-9 inches between each hole. I would have spread them out farther if I could, but my PVC isn't long enough.

We have an adjustable door knob drill bit that drills holes up to 3" wide, so I cut a skewer to 3" and found where on my plastic cups they have that diameter. Hold it up to the PVC and see if it's deep enough. It was. Unfortunately, the only drill we have with a chuck that could fit that bit was a hand drill. At first I tried the "drill a whole every millimeter and cut it out" method...but I didn't have the patience. Instead, I used a 2.5" drill bit and sanded the rest down with my Dremel. If you have to use a Dremel on plastic, make sure to wear a mask in a well ventilated area and clean up all the dust afterward.

Rinse the dust off of the pipes.

Step 6: Assemble

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Bring everything out to your final destination and set it up. Because mine is up against the screen of our porch, the lower side faces out, so everyone can get equal amounts of sunlight. Double check that the stands are all in the right orientation...i spent about 20 minutes trying to figure out why the water wouldn't run correctly.

I drilled three holes in the lid to my bucket, one for the intake tube, one for the output tube, and one for the power cord. It allows me to leave the lid on, and thus help prevent algae from growing.

Step 7: Cups

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Drill plenty of holes in the bottom and edges of each plastic cup, for the roots.

Use the cups to measure out clay balls into a bucket of water. The water will wash off any dust that has accumulated on them.

Step 8: Planting

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Carefully use a hose (I like the flat setting) to clean as much dirt as possible off the roots. Try not to mess them up...they don't like that so much. Once they're clean, surround them in the cups with clay balls. Use enough that they can support themselves and stand tall.

When you're arranging the plants in the system, keep in mind what kind of plant they are. Put taller plants in the back, so they don't block the sun. My plants that grow heavier veggies are on the lower section, so that I can build a table from the plywood and 2x4's to support their crops.

Step 9: Nutrients

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Mix according to the label. Mine required 20mL per 4L. Because I don't have any way of measuring mL, I converted it to about 4 tsp per 4L and mixed it in a 2L soda bottle. That was a pain. Next time I make it to the hydroponics store, I'm definitely buying a syringe.

  • Nutrient solutions come in all sorts of varieties. I bought a general purpose "grow" solution that also has a "bloom" counterpart for when the plant begins to...bloom.

Step 10: Maitenance

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The nutrients have to be changed periodically, and it's hard to tell when it needs to be done. People do it anywhere from once a week to once a month, and it depends on how much you mix at a time.

Hydroponics.net recommends that you add fresh water as it's used by plants, because even though water is absorbed, nutrients still remain, and can get more concentrated. They said that once you've added half the amount that was originally in there, it's time to change. So with my 7L, once i've had to add 3.5L of additional fresh water, the nutrients will be mostly depleted.

Some people also monitor their ph levels. Pool stores generally will check it for free. I don't have a lot of information on the subject to offer, however.

Other than that, there isn't a lot that you have to do except care for the plants as you usually would.

Step 11: Resources

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  • Instructables has a lot of great information on hydroponics
  • hydroponics.net has a good FAQ
  • SimplyHydro.com has a good explanation of some types of hydroponics

I hope this helps with designing your own system. Feel free to leave questions, comments, and most importantly, advice, below. Thanks!
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Wow! Awesome idea. I am definitely gonna make this
tintinescobar8 months ago
cool system im gonna use it for a school project!
tintinescobar8 months ago
cool system im gonna use it for a school project!
tintinescobar8 months ago
cool system im gonna use it for a school project!
tintinescobar8 months ago
cool system im gonna use it for a school project! ?
tintinescobar8 months ago
cool system im gonna use it for a school project! ?
tintinescobar8 months ago
cool system im gonna use it for a school project!
tintinescobar8 months ago
cool system im gonna use it for a school project! ?
sandworm1 year ago

I'm planning to build one of these soon, great work! One question, does it run 24/7, or do you have some sort of timer?

I noticed that you didn't mention much about figuring out correct flowrates. Is that because different plants require different flowrates? Or is that something you just left to trial and error?
Geoffrey983 years ago
Hey i was just wondering if that exact system could grow cacti or venus fly traps?
If you're still interested, I would recommend against it, but with effort it may be possible. A lot of cacti will suffer root rot if left that moist (some do okay, but you'd have to experiment). Carnivorous plants are from nutrient poor areas so the hydroponic solution would burn the roots. I suppose a hydro setup running distilled water would work to keep them watered, it would make it pretty easy to control how much they stand in.
jwood3113 years ago
Great job! Thank you!
I really hope I can pull this off. How long does the water last?
That will depend on your climate, plants and reservoir. I was generally able to just replace water as it was consumed every other week or so.
Thank you
g.forces3 years ago
Great system! Check out my hanging nft system at http://needscitation.blogspot.com/2012/03/nutrient-film-technique-hydroponics.html and tell me what you guys think about the design. Regards.
scottinnh3 years ago
A 'pipette' or 'wine thief' will sub for a syringe, and any home brewing/wine making shop would have it.
MrChuII3 years ago
Sweet setup! An even gentler way to remove dirt from roots is to submerge the root ball in water, gently moving the water to wash away the dirt. Just make sure you 1st adjust the PH of the water as it you were going to use it for the nutrient solution.
Goudla4 years ago
Nice work!
At some point, while following interesting biology classes in highschool, I also got interested into that, and I seem to remember that by monitoring the pH and the electrical conductivity of the liquid (nutrients), it was possible to control it.
This even makes it possible to adapt it to the actual needs of the plant, which can vary depending on the actual stage of development of the plant.
Finally, if you can control, and adapt the composition of the liquid, you don't need to replace/through any.
bountycrops4 years ago
Thanks for sharing this wonderful step-by-step process on building an NFT system. The PVC pipe would really do better with this kind of system although rain gutters would also do fine. I think the only challenge with rain gutters is to find a covering that will be light proof. Anyway, what kinds of plant have you tried growing with this system? Would be happy to know the results.
pyrofyr5 years ago
I see most other instructables use LECA on the bottom (Holy christmas batman, I just found out my home depot carries it, and it's cheap too), Vermiculite, and Perlite.

I can't find Vermiculite anywhere, and then I noticed you didn't list what you use besides LECA, did you use anything or just fill it up with  LECA?
Weissensteinburg (author)  pyrofyr5 years ago
Sorry for the late reply. I've made two hydroponic systems now, and both used only LECA. Some people seem to like mixes, but I haven't had any problems using only it.
tea-pain5 years ago
is pvc ok to use? its not toxic @ all?
Weissensteinburg (author)  tea-pain5 years ago
 PVC is only toxic when heated.
[AV3NG3R]5 years ago
LOL, I saw the NFT Acronym and assumed it was your secret code for "No F*cking Time"...

Awesome instructable though.
awang86 years ago
I've got a 500GPH Bilge Pump somewhere in the garage. Will it work? Or will it be too vigorous and damage the roots? I'm trying to make a nice 4-hole herb garden for my kitchen with all the needed herbs - rosemary, parsley, basil and thyme.
awang8 awang86 years ago
Sorry, one more question I forgot to mention. Are you sure that tiny hydroponics... thing... will be able to handle a mature tomato? Because i'm also planning on growing a few of those.
awang8 awang86 years ago
Gah... I hate it whem you just suddenly have a question pop up in your mind and just have to find out the answer. Can the roots breathe? Water doesn't loook like it has much air in it. Before I make another post, can seaweed solution (liquid fertilizer) be used instead of the hydroponics nutrients?
Weissensteinburg (author)  awang86 years ago
I've seen it's use mentioned, and don't think people generally recommend it over conventional nutrient solution, but I think it will work. Don't take my word for it, though.
Thanks alot.

1. I think the pump would still be good enough, http://Hydroponics.net sells 550GPH... So I'm guessing it isn't that bad.

2.Yep. I mean the nutrient supply.

3.Err... Uhh... Umm... I'll buy hydroponic nutrient some online.

I'll be buying a few bags of pelite and vermiculite. I beleive that mixed in a ratio of 3:1 would make a good growing medium.
A 500GPH pump will push almost 9 gallons of water per minute over the roots. You'll probably flood the tubes and the roots won't get the air they need.
For a small system you should probably use a smaller pump.
Hydroponics.net also supplies the professionals who would need a big pump.
Your bilge pump (if it has a float) might be good for the food and drain method.
What if we use the bilge pump with a flow regulator, or what if i use it for a drip system?
Since I'm not very... interested... in ebb and flow, and I don't want to buy a new pump, , I thought of an idea. At the hardware store there are chrome switches (designed for toilet cisterns) that can regulate the flow pretty damn good, down to a tiny trickle, and everything inbetween. So I might somehow attach a copper pipe to my pump, then use a olive threaded thingy to connect it to the cistern switch, then use another olive thingy and copper pipe to connect to the gutter (I'm using gutters, it's cheaper). there will be a hole at the top of the opposite end of the gutter where the water will come out and fall into a bucket containing the pump. The copper pipe, it's lurking in my garage: $0. 2 olive thingies: $4. Switch (or is it called valve?): $3. Seven dollars is cheaper than a new pump. Sorry about the long comment, but I just had to explain everything in detail.
Weissensteinburg (author)  awang86 years ago
In what sense? Depending on the plant, you may need a trellis to support it. If you mean the nutrient supply, than yes, it will. As long as water flows, it can get as much nutrient as it needs. That being said, some plants require more nutrients than others, and you'll have to replenish the supply more often.
Weissensteinburg (author)  awang86 years ago
I'm thinking that's a lot more than you need.
How did you get the stinking plastic out of the hole cutter?  I'mabout to pull my hair out.
I got it.  I waited to long to take it out.  I had to put iton a stove burner to get it out. 
just curious as to how much water you want moving across everything. like if i wanted to expand this to something bigger, could i still use that same size pump you are using, or would i want a bigger one
You should be able to use the same one. The flow of water really isn't as important as the fact that it is circulating. The reason you can't just stick a plant in the water is that the water needs to re-oxygenate, like in a fish tank.
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