NFT Hydroponics (Nutrient Film Technique: 3 Key Ideas)


The Nutrient Film Technique (NFT) is a simple yet effective hydroponic technique known for its large harvests and low maintenance. It’s ideal for fast-growing plants like leafy greens and a great addition for both beginner and expert gardeners alike. 

One of the most simple and popular hydroponic methods is the nutrient film technique (NFT). The NFT is notorious for its simplistic design, low maintenance, and high-quality harvests. In this article, we will cover what NFT hydroponic systems are, how they work, and answer some frequently asked questions.

Let’s get started! 

NFT Hydroponics 1
The Nutrient Film Technique (NFT) is a hydroponic method that uses minimal water (and no soil) to grow plants.

What Is NFT Hydroponics?

Hydroponics is a method of growing plants without the use of soil. NFT stands for Nutrient Film Technique, which is a technique that growers use when growing plants hydroponically.

The NFT is a growing technique where a thin stream of nutrient-dense water flows directly to the roots of plants and is redistributed through an active water cycle. This system is utilized by gardeners on both the hobbyist level and on the commercial scale. 

NFT Hydroponics 2
NFT uses a thin stream of water that has enough nutrients for plants to grow.

There are different ways in which you can grow plants hydroponically. Many hydroponic methods are similar to one another. The NFT is closely related to the “ebb and flow” hydroponic system; arguably the most common methods of hydroponics. But, the NFT is still very distinct in its procedure and benefits. 

NFT hydroponic systems use a water cycle run by both water pumps and gravity to deliver nutrient dense water your growing plants. But, what makes or breaks a good NFT system is how much nutrient solution flows over the roots of the plants. In the case of NFT hydroponic systems, less is more!

water pump
You will need a water pump to help circulate the nutrient-dense water in an NFT system.

The goal of an NFT system is to have a thin, film-like flow of water within the channels. The water should be shallow enough that only the ends of the roots are submerged.

Ideally, the upper roots will remain dry to ensure the plants can oxygenate. If too much water flows into the channels, the plants can drown or the roots can rot.

root rot
Root rot causes roots to turn brown and mushy.

Many growers favor the NFT because of how budget-friendly and low-maintenance it is! Some notable benefits of NFT systems are:

  • Does not require a growing medium
  • Extremely water efficient
  • Easy to monitor root health/quality
  • Easy clean and sanitize

Despite the great perks above, there are a few notable downsides to the NFT system that are important to be aware of:

  • Plants with larger root systems can cause clogging
  • Not ideal for plants that require support
  • Very sensitive to pump failure and power outages = plants will rapidly die without water

These downsides can be worked around or avoided with a little extra work and consistent monitoring. If you are new to hydroponics, it is truly a journey of trial and error to see what works for you and what doesn’t!

How Does An NFT Hydroponics System Work?

In an NFT system, the plants are positioned within small openings of an enclosed channel (many use PVC pipe as a channel). Imagine a pipe laying horizontally with holes cut out of the top that plants are growing out of.

A thin film of water flows through the channels, only touching the roots’ ends. This is achieved through pumps that push the nutrient water from a reservoir into the channels.

NFT Hydroponics 3
Plants in an NFT system are placed in small openings within the channel (often a PVC pipe).

The channels are intentionally set up at an angle, letting gravity pull the water down into a drain. The water is drained back into the reservoir, where it is ready to be used again. 

This technique is similar to the ‘ebb and flow’ hydroponic system. Both the NFT and ebb and flow systems use a pump to cycle nutrient-dense water to the growing plants and recycle the unused water back into the main reservoir.

The main difference between the two systems is that the NFT has water continuously flowing over the roots. In the ebb and flow system, the water flows through the trays multiple times in a single day with time in between cycles. 

seedlings
NFT provides a continuous supply of nutrient dense water to plant roots.

The NFT system has a constant flow of thin, film-like water, which is why it is called the nutrient film technique. The thin level of water nourishes the plants with nutrients and ensures they will not get too wet.

The shallow, continuous flow of water protects the plants from becoming too dry between cycles. The film of water only reaches the bottom of the roots while the upper parts of the roots remain dry. Because of this, the roots will have consistent access to oxygen.

NFT hydroponic systems are an active form of hydroponics. Active hydroponic systems use pumps to cycle water throughout the system and to the plants.

The opposite of active hydroponics are passive hydroponics. Passive hydroponics simply keep the plants sitting in still water as they grow.

Do You Need An Air Pump for NFT Hydroponics?

In NFT hydroponics, the flow of water is extremely shallow. Because of this, the upper roots of plants will always have access to oxygen. In NFT hydroponics, the roots should never be completely engulfed in water. Therefore, including an air pump is less crucial.

NFT Hydroponics 4
You do not need an air pump for an NFT system, but plants do need oxygen to survive, whether grown in soil or in a hydroponics system.

Despite this, incorporating an air pump is never a bad idea and will only benefit your plants. Plants need oxygen to survive!

Therefore, an air pump is certainly recommended. An air pump is absolutely essential in hydroponic systems that grow crops in deep water. Deep water culture hydroponic systems are an example of this!

Best Growing Medium To Use In An NFT Hydroponics System

In a nutrient film technique hydroponic system, a growing medium is only required when starting your plants. Once the plants have developed, the roots should grow directly into the streaming solution.  

If your plants of choice require a growing medium, the best-growing mediums for an NFT system are ones that have a low Water Holding Capacity (WHC).

NFT Hydroponics 5
After the plants in your NFT system are established, you won’t need a medium anymore.

In NFT hydroponics, the goal is to have a very thin film of water flowing over the ends of plants’ roots. Growing mediums with high WHC are going to absorb a lot of that water, making that constantly flowing film of water difficult to achieve. 

A growing medium option for NFT systems is pebbles/gravel. Pebbles give the plants the support they need without absorbing the nutrient water.

If you decide to include a growing medium into your NFT system, it is important to remember only to use it sparingly. If too much is added, it will interfere with the roots ability to reach the nutrient solution. 

What Can You Grow In An NFT Hydroponic System?

It is important to remember that the goal of the NFT system is to have plant roots directly within the flow of water. Therefore, light-weight plants that grow quickly do best in nutrient film technique systems because they do not require much support. 

Greens do fantastic in NFT systems because they will still thrive without a growing medium for support. It is because of their small root systems that a support medium is not necessary. Lettuce, kale, romaine, basil, and many other small-root greens do exceptionally well in NFT systems. 

NFT Hydroponics 6
Greens, such as lettuce, do great in an NFT system because they have relatively shallow roots and they do not grow too tall (until they start to go to seed!)

Additional plants known for doing well in NFT hydroponic systems are broccoli and cauliflower. These plants do not grow very large and remain light-weight. Their small root systems and ability to support themselves are ideal for an NFT system!

What about fruiting plants? Fruit-producing plants like cucumbers and squash require much more support.

Squash and other fruiting plants can grow quite tall and may need support. To grow them, you might need extra equipment for your NFT setup.

Although it is possible to grow fruiting plants within an NFT system, it takes a bit of extra work. You will have to establish the necessary support structures for the plant varieties and nurture them to grow along the structures. 

Fruiting plants also have larger root systems which can cause clogging in NFT hydroponics. If you decide to add plants with large root systems into your NFT hydroponic system, it is vital to monitor the roots to prevent potential clogging. If the clogging stops the water flow for just a few hours, you could lose all of your plants. 

Can You Grow Tomatoes In An NFT Hydroponic System?

NFT hydroponic systems may not be the ideal choice for tomato plants. Yet, they can certainly do well under the right conditions and with some extra work.

Tomato plants are vine crops and therefore be in need of lots of support that basic NFT systems do not offer. For that reason, some extra work is necessary to create support structures for the tomato plants.

NFT Hydroponics 7
Most tomato varieties will grow quite tall (4 to 5 feet or more), so they will probably need support in an NFT system.

It is also good to note that NFT hydroponic systems are ideal for plants with small root systems. Tomato plants have larger root systems because they need to support themselves as they grow tall.

This can be accommodated for via larger channels in your NFT system. It is important to remember to monitor any large root systems in NFT hydroponics to prevent any preventable clogging!

tomato plant no leaves

Some alternative hydroponic systems are more suitable for tomato plants. The ebb and flow systems and hydroponic drip systems are extremely tomato-friendly!

(If you don’t want to provide tall supports, you might want to try some tiny tomato plants that only grow to a height of 12 inches – you can learn more here!)

Conclusion

Growing crops hydroponically is incredibly sustainable, efficient, and rewarding. Nutrient film technique hydroponic systems offer simplicity and worth-while benefits for first-time hydroponic gardeners and experts alike. And they are a whole lot of fun!

You can also try Kratky hydroponics, an alternative to NFT hydroponics.

DWC hydroponics is another alternative method you might want to read up on.

You can learn more about hydroponic gardens here.

You can find out how to grow hydroponic microgreens here.

If you are interested in hydroponic towers, check out this article.

About the author:
Sofi is a passionate writer who studied communications and environmental studies at Eckerd College. You can get in touch with Sofi at https://slenzi4.wixsite.com/website.

Sofi L.

jonathon.david.madore

Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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