Nutrient film technique hydroponic gardens are a very similar system to ebb and flow. The difference is that the nutrient solution is continually flowing over the roots, instead of being allowed to be drained off. This works because of a great thing called gravity. The grow tray in this system is placed at an angle so that the water can be pumped in at the top of the tray, flow down, drain out at the bottom of the tray, and be sent through the system again.
Nutrient film techniques got its name because the nutrient solution flows as a thin film over the roots. This means that they are well-fed, but not completely soaked. The upper parts of the roots stay dry and get plenty of air and oxygen. This system works best for plants that are lightweight and grow fast. Proper support systems such as trellises would be needed for larger plants. Since the roots are free hanging and not supported by a growing medium in this system, a top-heavy plant would not work very well.
Build Nutrient Film Technique Hydroponic Garden
There are many possibilities for building your nutrient film technique hydroponic garden. Smaller systems using a tray, similar to the ebb and flow system, can be constructed. These could be great for indoors or smaller spaces such as a deck. However, the instructions that follow are for a cool, large outdoor system. This can truly turn your backyard into a high yield farm if you build several of these units.
Here is a list of the supplies needed:
- (8) 8-foot 2x4s
- (3) sawhorse brackets
- (18) metal curved plant hangers with screws
- (8) 3” PVC pipes in 10-foot lengths
- 3” PVC shorter sweep elbow
- 3” PVC pipe end cap
- 6 feet of ¼” black tubing
- 70-gallon container with a cover to serve as the reservoir
- A submersible pump (550gph)
- 10” pump bag
- (120) 2” net cups
- (120) 1.5” Rockwool plugs or accelerant starter plugs (or desired to grow media, enough to fill the (120) 2” net pots)
- 1.5” self-feed bit
Do some research and decide on the nutrients you would like to use on your system. A few good choices would be FloraGro, FloraMicro, or SOS Beneficial Bacteria.
- Connect the 2x4s to the sawhorse brackets so that there are 3 sets of A-frames.
- Dig holes where you would like to set up the system. Place the A-frame sets at no more than 3.5’. Bury each leg of each A-frame about a foot deep at an angle.
- Attach one of the remaining 2x4s across the top of all three A-Frame sets. This will stabilize everything and give a solid frame to work on.
- Grab the metal plant hangers and screw them into the A-Frame sets at a gradual angle, at no more than a 2% gradient, so the water is not gushing down the system.
- Drill holes that are 1.5” in diameter in the PVC pipe, about 6” apart. This will allow the 2” net pots to sit in the holes without falling all the way through. When finished, there should be about 120 holes.
- Place the PVC pipes on the hangers. These may need to be cut as they reach the end of the A-frame. Use the sweep elbows to connect the pipes as they zig-zag down the A-frame structure. It may be good to use some waterproof PVC glue to fasten the pipes to the elbows just to make sure there is no leaking.
- At the end of the run, tighten the short sweep elbow to the end of the pipe. This will go into the water reservoir.
- Drill a ¼” hole in the end cap and place it on the front of the very first PVC pipe at the top.
- Push one end of the ¼” tubing into this hole and connect the other end to the pump. Put the pump in the pump bag and ensure the tubing and pump cord are going through a hole in the reservoir cover.
- Place the short sweep elbow over the port of the reservoir cover. This will get the water flowing back into the reservoir. It could be a good idea to bury the reservoir so that the summer heat does not affect the solution in the reservoir; it is best to keep this cool.
- Fill the reservoir with water and nutrient solution. Also, check the system pH and adjust accordingly. Plugin the pump and test the system to make sure everything is working properly.
- Place one net pot in each hole and add growing medium as well as seedlings. This system does not allow to grow plants from seeds, as the water never reaches the top of the pot. Top watering may be needed for a few days just to get the plants established.
Maintaining Nutrient Film Technique Hydroponic Garden
Keep in mind that this system works best for plants with small root systems. Greens and herbs are really good choices. Plants that grow large or just have large root systems will clog it. Start your seeds elsewhere or purchase seedlings from the garden centre. If you buy seedlings from the garden centre, just gently wash off the soil from the roots. Then, it will be ready to go into the growing medium, and the roots should hopefully be long enough already to reach the nutrient film running by.
A Nutrient Film Technique Hydroponic Garden System needs to run 24 hours a day. The reservoir should be completely flushed, cleaned, and stocked with a fresh batch of nutrient solution every two to four weeks. Between these times, keep an eye on the pH and nutrient levels in the water. Also, make sure to take out any plants that are getting old and may have large root systems that are clogging the system. Plants grow fast and well in this system. With 120 holes, this system will provide a high yield. It is best to plant a variety of things so that you do not end up with a freezer full of just one thing.