NFT is a re-circulating continuous flow hydroponic system, which uses no growing media except for any starter blocks used. In this growing method, the plants rest in a flat, but sloping tray or channel (gully), often with no support, but using propagation cubes/sponges or small net pots filled with coco coir. A thin ‘film’ of nutrient solution continuously flows down a shallow channel with a slight incline. It is essentially a bare-rooted growing method that has the roots growing out of the planting block to spread across the channel and form a ‘root mat’. It is important that the roots are always in contact with the air allowing easy access to oxygen.
As the system is usually run on a constant basis (during daylight hours) the management of NFT systems has to be more diligent than other types of systems. Should the re-circulating pump fail, the plants will die due to lack of growing media to hold water and food for them. Regular ‘solution changes’ are required to refresh the nutrient solution – the more frequent, the better – and the reservoir should be maintained as close to full as possible to prevent EC, pH and temperature fluctuations.