NFT or nutrient film technique systems are characterized by a permanent flow of nutrients in a thin "film" around the roots. A pump transports the nutrient solution on an inclined plane (e.g. a tube), on which the plant roots lie. They are continuously watered and supplied with nutrients. The constant flow prevents nutrient accumulation.
Owing to the special construction of NFT systems, oxygen is inserted into the nutrient solution, usually through downpipes or vortex systems. In most cases no substrate is used, so that the roots have unhindered access to nutrients and oxygen and can grow quickly.
It is commonly used for growing smaller quick growing plants like different types of lettuce，herbs and greens leaf vegetables.
The advantages of NFT hydroponics system: safety; saving land and water resources; saving labor; effectively reducing the use of fertilizers and pesticides; high yield and high quality vegetables; environmental control; no need for continuous cropping.