If you have seen rows of lettuce growing from long channels, you were probably looking at NFT. The name stands for nutrient film technique, referring to the shallow layer of nutrient solution that passes beneath the roots.

NFT systems can look quite different, but they all follow the same principle. A timed pump sends a shallow film of nutrient solution through slightly sloped channels feeding the roots. Gravity carries the water back to the reservoir.

What every NFT system has in common

  1. A shared reservoir holds the nutrient solution.
  2. A pump moves the solution to the higher end of the channels.
  3. A shallow film passes beneath the roots without fully submerging them.
  4. A slight slope allows gravity to return the solution to the reservoir.

Only the bottom of the roots needs to touch the moving film. The rest has access to air. Every channel still needs a reliable and even flow of water.

Round pipes, stacked systems and NFT gullies

Stacked NFT systems arrange the channels across multiple levels. They provide more planting sites within a smaller footprint, although the upper rows can shade the plants below and every channel still needs the correct slope and water flow.

The channels themselves also vary. DIY systems often use round PVC pipe, while purpose-built NFT gullies usually have a wider, flatter base that spreads the nutrient film more evenly and gives the roots more room. Some commercial channels also have removable lids, which makes blocked roots and plant debris easier to reach when cleaning.

What grows well in NFT?

NFT is most commonly used for lettuce, basil, herbs, Asian greens and strawberries. These crops have relatively compact root systems and do not need the heavy structural support required by large fruiting plants.

Next steps

If you are still comparing NFT with other methods, return to the beginner hydroponic system guide. It compares NFT with Kratky, DWC, countertop gardens, towers and Dutch buckets.