The Nutrient Film Technique (NFT) is a hydroponic system that delivers a thin, continuous flow of nutrient-rich water to plant roots. This method ensures optimal oxygenation and nutrient absorption, promoting rapid growth and high yields. This guide explains how NFT systems work, their benefits, and how to set them up and maintain them effectively for cannabis cultivation.
1. How NFT Works
- Flowing Nutrient Solution: A shallow film of nutrient-rich water flows through sloped channels, bathing the plant roots.
- Oxygen Availability: As roots are partially exposed to air, they receive excellent oxygenation, enhancing growth.
- Recirculation: The nutrient solution is collected in a reservoir and recirculated continuously to minimize waste.
2. Benefits of NFT
- Efficient Nutrient Delivery: Direct contact with the nutrient film ensures rapid absorption and minimal waste.
- Oxygenation: Exposed roots receive ample oxygen, reducing the risk of root rot.
- Low Water Usage: Recirculating water reduces overall consumption, making NFT an eco-friendly option.
- Scalability: NFT systems are adaptable for both small and large grow operations.
3. Setting Up an NFT System
- Materials Needed:
- Growing channels or tubes with a slight slope for water flow.
- Net pots to hold plants.
- Hydroponic medium (e.g., rockwool or coco coir plugs).
- Reservoir for nutrient solution.
- Submersible pump and tubing to circulate the solution.
- pH and EC meters to monitor nutrient solution quality.
- Step-by-Step Setup:
- Place the growing channels at a slight angle to allow water to flow naturally.
- Position plants in net pots along the channels.
- Fill the reservoir with water and add hydroponic nutrients, maintaining an EC of 1.0–2.5 mS/cm and a pH of 5.5–6.5.
- Connect the pump to circulate the nutrient solution through the channels.
- Ensure the solution returns to the reservoir for continuous recirculation.
4. Maintenance and Monitoring
- Check Nutrient Solution:
- Monitor pH and EC levels daily and adjust as needed.
- Replace the solution every 1–2 weeks to prevent imbalances.
- Inspect System Components:
- Clean the channels, reservoir, and pump regularly to avoid clogs and algae growth.
- Monitor Root Health:
- Healthy roots should be white and firm. Brown or slimy roots may indicate a problem with oxygenation or solution quality.
5. Troubleshooting Common Issues
- Algae Growth:
- Cause: Light exposure to nutrient solution.
- Solution: Cover channels and the reservoir to block light.
- Clogs in Channels:
- Cause: Accumulation of debris or roots blocking flow.
- Solution: Clean channels regularly and prune overgrown roots.
- Nutrient Imbalances:
- Cause: Inconsistent solution monitoring.
- Solution: Check and adjust pH and EC daily.