What is NFT? A Constant Flow of Life

Nutrient Film Technique (NFT) is a widely adopted hydroponic method where plants are grown in shallow channels or gullies. A very thin, continuous film of nutrient-rich water flows constantly over the bare roots of the plants, providing them with all the necessary dissolved nutrients and oxygen. The water then recirculates back to a reservoir, creating a highly efficient closed-loop system.

• Rapid Growth & Nutrient Uptake: Roots have constant and direct access to water, oxygen, and nutrients, leading to accelerated growth rates and efficient absorption.

• High Water & Nutrient Efficiency: The recirculating nature and minimal water volume in the channels drastically reduce water and nutrient waste.

• Space Efficient: NFT systems can be easily stacked vertically, maximizing growing space, particularly beneficial for urban or indoor farms.

• Clean & Sterile: Without traditional growing media, NFT systems are generally cleaner, reduce the risk of soil-borne pests, and simplify cleaning.

**Note:** NFT systems require precise setup and diligent monitoring, as they offer little buffering against system interruptions compared to media-based methods.

Key Components of an NFT System

Building an NFT system involves assembling a few specialized parts that work together to create the continuous flow:

• Nutrient Reservoir: A light-proof container positioned at the lowest point of the system to collect and hold the recirculating nutrient solution.

• Submersible Pump: Placed in the reservoir, it continuously pumps the nutrient solution up to the highest end of the NFT channels.

• NFT Channels / Gullies: Long, shallow, watertight channels (often made of PVC or specialized hydroponic plastic) where plants are placed. These must be sloped to allow gravity to return the solution.

• Manifold & Delivery Tubing: Connects the pump to the channels, distributing the nutrient solution evenly to each one.

• Net Pots & Collars: Small net pots hold the plant (often in a minimal inert medium like rockwool cube) and suspend it in holes on top of the channels, allowing roots to dangle into the flowing film.

• Support Structure: A sturdy frame or bench to hold the channels at the correct slope above the reservoir.

Operating Your NFT System: Precision is Paramount

The success of NFT hinges on maintaining precise conditions, particularly the slope and flow rate.

• Channel Slope: A gentle slope is crucial. Typically, a gradient of 1:30 to 1:100 (1 inch drop per 30-100 inches of length) is recommended. Too steep, and the film won't be consistent; too flat, and pooling/stagnation can occur.

• Flow Rate: Aim for a flow rate of about 1 liter per minute per gully. Too fast can deprive roots of oxygen; too slow can lead to nutrient depletion down the channel.

• Continuous Flow: Unlike Ebb and Flow, NFT typically runs continuously (24/7), providing an uninterrupted supply of nutrients and oxygen.

• pH Control (5.5 - 6.5): Consistent pH is vital for nutrient availability. Monitor daily and adjust with pH Up/Down.

• EC/PPM Monitoring: Regularly measure nutrient concentration. Perform full reservoir changes weekly or bi-weekly to prevent imbalances and salt buildup.

• Nutrient Solution Temperature (65-72°F / 18-22°C): Maintaining this temperature is critical to prevent root disease and ensure high dissolved oxygen levels.

**Maintenance:** Regularly inspect channels for clogs, especially from root growth. Keep nozzles clean, and ensure the system is light-proof to prevent algae in the solution.

Suitable Plants for NFT Systems

NFT is best suited for plants that grow relatively quickly and have a less extensive root system that won't easily clog the channels.

• Leafy Greens: Lettuce (all varieties), spinach, kale, Swiss chard, and other fast-growing leafy vegetables are ideal.

• Herbs: Basil, mint, cilantro, parsley, chives, and other culinary herbs thrive in NFT systems.

• Strawberries: Compact strawberry varieties can be successfully grown in NFT, especially in vertical configurations.

• Avoid: Large fruiting plants like tomatoes, peppers, and cucumbers are generally not recommended due to their heavy weight and extensive root systems that can easily clog the thin channels. Root vegetables are also unsuitable.