Nutrient Film Technique (NFT)
Definition - What does Nutrient Film Technique (NFT) mean?
Nutrient film technique (NFT) is a continuous flow style of hydroponic growing that is common among cannabis cultivators. It is one of the six main types of hydroponic systems and is known for its efficient use of water, ease of set up, and accurate feeding results.
In an NFT set-up, a small, shallow stream (film) of nutrient-rich water is provided to plant roots via a long channel, gutter, or tube. NFT systems are usually all-in-one, closed systems, where a large container holds the pump and nutrient mixture within the same system, facilitating a continuous flow of aerated nutrients to the roots that are housed in a long narrow channel. The runoff nutrient mixture is then lead back into the main water container.
Hydrolife explains Nutrient Film Technique (NFT)
The nutrient film technique is similar to the ebb and flow hydroponic technique, as they both utilize a pump to move nutrients in a continuous, constant flow. However, with NFT the solution flows directly over the roots. However, the nutrient solution does not completely soak the roots; the upper part of the roots remains dry.
NFT systems use shallow tubes that are slightly angled so that the pump moves the nutrient solution to the higher areas of the system. The nutrient solution slowly moves by gravity to the lower areas. A tube system with holes bored for the plants is used instead of trays, making it easier to angle for proper flow over the roots.
Some cannabis growers plant directly through the holes, but it is okay to use net pots, and many cultivators use no planting medium with the nutrient film system. In this case, the roots fall through the net directly into the nutrient solution.
When using the nutrient film technique it is important to not try to grow heavy plants that require a lot of support. This is because the roots are not in a medium that can sustain the heavy weight of a heavy plant.
Because NFT systems require moving parts and electricity, they are considered active systems. The main drawback being that in a power outage, entire yields can be destroyed if there is no back-up plan.