Nutrient Film Technique NFT
Nutrient film technique hydroponics involves a system in which the plant is suspended over a small enclosed tray or trough. The trough contrains a light flow of a nutrient enriched solution which the roots of the plant have access to 24/7. The trough is set at an angle that allows the solution to drain the be recirculated by a water pump.
NFT could be considered by some as the best method for growing hydroponic lettuce, although raft hydroponics would be a productive system as well. Usually this type of system is reserved for plants that do not produce a large root mass. Younger plants or lettuce would be an ideal choice As the root mass could hinder the flow of the solution. Idealy the roots of the plant have constant access to oxygen and that the plants have access to as much or as little water as they need.
Often a grow medium isn't used to contain the plant and instead a plug is used to hold the plant from the stem as the roots grow from underneath
How does Nutrient Film Technique (NFT) hydroponics work?
- The water reservoir mixed with the nutrient solution
- A pump is used to circulate the water throughout the system
- The solution is pumped to one end of the rail
- The rail, (placed at a slight slant) allows the nutrient to be absorbed by all plants
- The solution reaches the end of the rail and is drained back into the reservoir
The drawbacks of running Nutrient Film Technique (NFT) is that you limit the type of plants you can grow hydroponically. Also because of the limited rate of flow that is ideal for NFT 1-2 L/min plants place at the end of the run or gully maybe have less nutrient available than plant placed towards the beginning. NFT systems such as this are typically more susceptible to algae, evaporation and water temperature swings because of the low flow.