What is the Nutrient Film Technique (NFT)?
Nutrient Film Technique (NFT) also known as Nutrient film Transfer is a very popular technique for growing smaller hydroponic plants like lettuce, spinach, herbs, and spices. Even though its most commonly used in commercial systems it is becoming a hobbyist favorite due to ease of setup, use, and management. The NFT system is used in multiple different types of hydroponic systems. It is very easy to scale and can be modified and set up as a hybrid of multiple other techniques.
Nutrient Film Technique History
- 1965- The Nutrient Film Technique (NFT) was invented by Allen Cooper a scientist at Glasshouse Crops Research Institute in Littlehampton England. Cooper strived to create a system with long plastic trays to run a very shallow film of nutrient-rich water (nutrient film) to feed the plant root mats that would collect at the bottom of the trays.
- 1979 – Cooper published the book The ABC of NFT
- 1980-1990 – NFT systems are used by many commercial growers in Europe, mostly for lettuce.
How Does an NFT System Work?
- The NFT system is an Active Hydroponics system. A submersible pump in a reservoir pumps water and nutrients through a series of tubes and valves up to the higher end of a series of long channels, tubes or trays run side by side.
- The NFT trays are situated to have one side higher than the other
- The nutrient water uses gravity to flow down the length of the trays feeding all the plant root mats on the way to the lower end.
- Plants are either placed directly into an NFT tray or are grown in stone wool grow cubes then placed into the tray. In some homemade or DIY Hydroponic systems they are placed in a Grow Cube in a net cup then placed into a 3” PVC NFT pipe or 3 or 4” square PVC fence post sleeve.
- The water pump usually runs continuously but can be set on a timer
- Usually runs with an integrated aeration system but it is not required.
Pros of an NFT System
- Grow anywhere
- Grow year-round
- Portability (Take your garden with you if you move)
- Reuse water (Use at least 20x less water than the conventional garden)
- Reduces nutrient runoff into the environment and water systems
- No pesticides (or fewer pesticides)
- Need Less space to grow
- Less manual labor
- Plants grow faster
- Depending on the system design, Can be easier to harvest
- No critters
Cons of an NFT System
- The more expensive initial set up than conventional farming
- Requires constant power and power back up
- Need high-quality filtered water.
- Diseases have the potential to spread quickly to other plants in the same system.
- Mistakes in PH or Nutrient can be costly and deadly to your plants
- Requires more attention to PH and Nutrient balance.
The NFT system is a commercial and hobby grower’s favorite for ease of set up, use, and maintenance. Easily expandable, either horizontally and/or vertically, this system provides tons of room for growth. Many growers have seen added success in growth and plant health by adding aeration and a timer to the nutrient delivery system. Aeration adds additional oxygen to the water which aids in plant growth and prohibits some algae and harmful bacteria growth. The timer allows for the plant’s root matt to be exposed to even more oxygen for additional time periods. Since the water pumps are on for less time, you will notice considerable power savings. This is an active system so it will require a pump to deliver the vital nutrient solution so it if you are attached to your plants you may want to think about a battery backup or alternative power plan in case you lose power.