The main components of an NFT system are the same as Ebb and Flow—the difference is their configuration.
You can either place seedlings directly into the holes of your PVC pipe or channel or for greater stability plant them in net pots and place the net pots in the holes. Most people do not use a growing medium with NFT, but let the roots fall directly through the net pots and onto the film. If you choose to use a growing medium, use it sparingly and make sure that the roots have plenty of room to fall through the bottom of the pot. Whichever way you choose to plant your seedlings, make sure to check and trim the roots often to prevent out of control growth that can clog the system.
The nutrient solution flows in a thin film over the roots, ensuring that they are watered and fed but not completely soaked. The thin film ensures that the upper part of the roots will remain dry and have access to oxygen in the air.
Nutrient Film Technique uses tubes or channels instead of flat trays for the grow tray. This makes it easier to set it at an angle and to make sure that the nutrient solution flows directly to the roots without wasting any of it. Most often in DIY systems, a round tube or PVC pipe is used, with holes drilled to fit the net pots and seedlings. This has the advantage of being cheap and readily available to the home hobbyist.
Nutrient Film Technique works best if you choose plants that do not require a lot of support- lightweight, fast-growing plants that can be harvested quickly. If you want to grow plants such as tomatoes or squash, just make sure that you have proper support systems in place such as trellises. The roots are not suspended in a growing medium in this system, so they cannot handle supporting a lot of weight from a top-heavy plant.
The reservoir is placed in the grow tray, connected to the channel by a pump on the high end and a drain tube on the low end. You must also place an air stone in the reservoir, connected to an air pump outside, to oxygenate the water. Unlike other systems, the NFT does not use an automatic timer connected to the water pump because the pump runs constantly. This can be a big problem in the case of power outages, blockages or system failures, so make sure to check the pump and fill tube regularly and have a backup ready.
Nutrient Film Technique, or NFT, is a popular and versatile hydroponics system. It is similar to Ebb and Flow in that the system uses a pump to deliver fertilized water to the grow tray and a drain pipe to recycle the unused nutrient solution. The difference is that in NFT the nutrient solution is continuously flowing over the roots. This is accomplished using gravity. The grow tray is placed at an angle to allow the water to flow down towards the drainpipe, and a new solution is constantly being pumped into the high end of the tube. NFT is an active system, meaning it relies on moving parts to work. Passive systems such as Wick Systems have no moving parts.
The main disadvantage of using PVC as your grow tray is that the film will not evenly coat the roots. The roots in the middle would have access to a deeper depth of solution, while those closest to the edges would only have a shallow depth. This can cause uneven growth and weakness in your plants. By using a flat-bottomed channel, this problem is eliminated. Channels can also be easily built at home using simple materials such as 2×4”s and waterproof plastic lining.
Another important consideration is the length of your grow tray. As the nutrient solution flows over the roots, it decreases in nutrient concentration and oxygen levels. “Short-run” trays offer an advantage over long ones because they ensure that plants at the end of the line receive a nutrient solution with the same composition as those at the beginning of the line. Long channels can be used successfully, just make sure that you regularly check the nutrient levels and pH and replenish your solution. If you notice the plants at the end of the line growing more slowly or not producing as much, consider switching to a short run system.
Learn how to use the simple and easy Nutrient Film technique in your gravity fed hydroponics garden system with this helpful guide.
CropKing offers a variety of affordable NFT systems, including small introductory systems that are suitable for home hydroponics beginners and hobbyists, along with system components and growing supplies.
There’s one other reason to go with shorter channels: they’re less likely to sag. When setting up your NFT hydroponic system, you need to take great care that your growing channels are correctly aligned to the desired slope and are well supported. It’s a good idea to check the integrity of your system before you begin growing plants by running plain water through it. And you should continue to watch out for sagging during use, as this will disrupt the flow of the nutrient solution.
Providing plenty of oxygen to plant roots is one of the key concepts behind hydroponics. While plants need carbon dioxide for photosynthesis, their roots need oxygen to facilitate the absorption of nutrients. And when their roots have greater access to oxygen, plants grow faster.
As for the ideal length of the growing channels, they should measure no more than 35-40 feet (about 10-12 meters). Any longer, and you risk depriving plants located at the far ends of the channels from where the solution enters, since roots have been absorbing nutrients from the flow of solution all along the way. Shorter lengths will also make your system more versatile in terms of space usage, allowing for system designs such as a single loop made of a series of channels, a circuit with channels in parallel alignment, and vertical systems.
As we’ve seen, the growing chambers for nutrient film technique hydroponics need to be in the form of long, thin channels that are positioned on a slight incline, in order to create the shallow stream of nutrient solution that gives the system its name. (You’ll find a discussion of flow rate and channel slope at the end of this DIY guide.)
NFT hydroponics is a method of soil-less cultivation where plant roots are suspended above a stream of continuously flowing nutrient solution that provides them with all the water, nutrients, and oxygen they need to sustain rapid, healthy plant growth.
The term “nutrient film” refers to the ideal situation of having a constant shallow stream of nutrient solution passing over the roots. This ensures that only the bottom part of the root mass will be submerged in the nutrient solution, while the upper part is left exposed to the humid environment created inside the growing chamber, thus providing the roots with an abundant supply of oxygen.
Another consideration in choosing a pump for your NFT system is that you may want one that has an adjustable flow rate that you can easily modify according to the changing needs of your plants as they grow.
Also keep in mind that you will need to monitor the solution level in the reservoir as well as the pH and nutrient levels of the solution and make adjustments as needed.
NFT hydroponics is a type of soil-less cultivation. This article outlines all you need to know to get started growing plants with nutrient film technique.