Getting Started with NFT Hydroponics for Leafy Greens

The nutrient film technique, or NFT, is one of the most widely used hydroponic methods for lettuce and herbs. It uses little water, fits neatly into greenhouses, and produces clean crops that are easy to harvest.

How NFT works

Plants sit in holes along a gently sloped channel. A thin film of nutrient solution flows along the bottom of the channel, passing over the roots before draining back to a reservoir, where it is pumped round again. Because the film is shallow, roots take up water and nutrients while still having access to air.

Why it suits leafy greens

Lettuce, leafy greens and many herbs have compact root systems and short growing cycles, which makes them well suited to shallow channels and quick turnover.

What you need

• Hydroponic channels with planting holes, and a frame to support them at a slight slope.
• A reservoir, pump and return pipework.
• Net cups and a starting medium such as cocopeat.
• A hydroponic nutrient formulation.
• pH and EC meters to monitor the solution.

Key points to manage

• pH: most leafy crops take up nutrients well when the solution is kept slightly acidic, commonly around 5.5 to 6.5.
• EC: electrical conductivity shows the strength of the nutrient solution. Follow the nutrient supplier’s guidance for your crop and check it regularly.
• Flow: keep the film continuous, and check channels for blockages from roots.
• Solution temperature: warm solution holds less oxygen, which stresses roots. In hot climates, shade the reservoir, insulate pipework and use greenhouse cooling to keep temperatures down.
• Hygiene: clean channels and the reservoir between crops.

Explore our greenhouse and hydroponics range, or talk to our team about components for your system.