There are a few types of hydroponic systems: Water Culture, Ebb and Flow (Flood & Drain), Drip (recovery or non-recovery), N.F.T. (Nutrient Film Technique) and Aeroponic. We already listed the benefits of a vertical aeroponics system here, in this article I want to show you how to set up a simple NFT downspout Hydroponics system.
Why Choose Hydroponics?
Hydroponics allows us to grow food year-round despite our cold climate.
By definition, Hydroponics is a method of growing plants in a nutrient rich water solution. Instead of using soil the root system is supported by an inert medium such as vermiculite, rock wool, peat moss, or clay pellets.
Hydroponics gives you the ability to precisely control the variables that affect how well your plants grow. A fine-tuned hydroponic system lets the plants mature up to 25% faster and give up to 30% more yield by consuming less water when compared to growing in soil.
What is NFT Downspout Hydroponics?
Nutrient Film Technique (N.F.T.) Downspout Hydroponics is an exceptionally simple hydroponics setup. Nutrient enriched water is pumped into a vinyl downspout, drifts over the exposed roots and is drained back into the reservoir. Normally in the N.F.T. system, the nutrient solution is being pumped continuously, but we are experimenting with 15 minutes cycles during the day, and 30 minutes at night. Pumping in intervals helps to get more oxygen to the roots between the pumping cycles. However, it’s also important to dissolve as much oxygen in the solution as possible via an air pump and airstone (a.k.a. aquarium bubbler).
The downspout pipe can be as long or short as you want it to be. It also can be set up at different levels, as long as water flows through it, it will work.
Every time water flows through the system, the roots of the plant are watered and nourished.
Planting for downspout hydroponic is just the same as any hydroponics, read more on planting a hydroponic garden here.
Materials needed for the setup
- White Vinyl downspout
- Amerimax White Vinyl A-Elbow
- Amerimax downspout flex elbow
- Submersible fountain/pond pump (200-300 gph)
- 1/2 Barbed elbow fitting
- Roll 1/2″ tubing
- U-hook (4-pack)
- Electric drill with a 2” hole saw
- 2” round net pots (pot should have a rim that makes it slightly larger than 2”)
- A large clean plastic tub with lid (25-30 gal size works well)
- Zip ties
How to set up an NFT downspout Hydroponics system
Drill 2” holes every 6” in the top/wide side of the downspouts. TIP: Before drilling ALL the holes insert the 2” net pot in the first hole to make sure it sits well and doesn’t fall through.
When installing the U-hooks to support the downspout you need a slight decline (0.5in over 10ft) toward the reservoir end of the system, so the water can flow smoothly but not too fast. The other reason for the very small slope is shown in the next picture.
There you see a green plastic plate inside the downspout with a rectangle hole in the centre. The purpose of it is to hold back the water and raise its level so it would irrigate the rockwool cube in the net pot, as the net pots are not long enough to reach to the bottom of the downspout. This is important for young seedlings when the roots are not long enough to reach the bottom of the downspout pipe.
The two notches at the bottom of the green plastic barrier allow draining of the water between the pump run cycles. That allows exposing plant’s roots to the oxygen in the air which equals faster growth.
We have set up the 20′ long NFT downspout system alongside the windows of the winter garden using the U-hooks. However, you can adjust the length of the downspouts to the total width of your windows or available space.
Fasten the downspout to the support U-hooks using zip ties. Drill a small hole on the top side on the higher end of the downspout for the barbed elbow fitting. Connect it with the tube to the pump in the reservoir. You can plug off that end with an Amerimax white vinyl A-elbow pointing up. The other possibility is heating up with a heat gun about 2″ of the underside of the downspout and pushing it up to close the opening of the pipe as shown in the left picture below. The right picture demonstrates the closing of the pipe with an A-elbow. In addition, it is important then to seal all pipe connections with a food-grade silicone to prevent any leakage.
Install an Amerimax downspout A-elbow on the other end of the downspout and connect it with the flex elbow to the reservoir for drainage.
We have been testing the N.F.T. downspout hydroponics setup for a few months to see if it performs as promised. Seedlings have grown nicely into healthy lettuce plants and there have been no issues with it. It is an inexpensive setup for home growers allowing us to grow our own lettuce year-round, here are 3 reasons why grow your own salad greens.
See also an upgrade in this NFT system with bigger pipes for bigger plants here.
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That N.F.T. downspout hydroponics setup is cool!
Thank you, we like it a lot. a simple and inexpensive way to grow lots of lettuce even in the winter.
Definitely something to consider- we’re not as cold as you, but in 5a our seasons are also drastically short. What is your ambient temp for the grow room on average?
We try to stay above 13C (55F) in the room and have a heater in the water. On sunny days it gets much warmer than this but on cold overcast days, we hardly go above 15C. Lettuce seems to be fine with it.
How many sunlight hours are needed for lettuce? I have a large south-facing window I’d like to try this on, in 4b Wisconsin.
Lettuce is a short-day plant, meaning 10-12 hours are good for it. Being so far north, we do not get that many hours. In Wisconsin, you are quite a bit south of us, you have longer days in the winter. You should be able to grow at least as good as we do.
You did not list the air pump in your material list or what you add for nutrients.
Could you expand on this?
We do not use an air pump, our big system has worked great so far without. But a small system could use one if the water is not circulating enough. For nutrients we like General Hydroponics MaxiGro, it is inexpensive and works great.
What did you use for the green plate to restrict the water flow?
I used a thin HDPE cutting board.