Nutrient film technique (NFT) is a hydroponic technique wherein a very shallow stream of water containing all the dissolved nutrients required for plant growth is re-circulated past the bare roots of plants in a watertight gully, also known as channels.NFT was developed in the mid 1960s in England by Dr.Alen Cooper.
It all mentioned above. You have a tank (reservoir) which has your water and nutes in. Connect a pump running 24/7 to a tray sitting on top, this has a spreader mat on which the roots attach to growing from rockwool cubes. The solution gets pumped up and as this tray is sloped the solution runs back into the reservoir via wee holes. The solution falling back in bubbles the water giving it oxygen in a way. The tray with the mat needs to be covered so the roots are not exposed to light (obviously). Only downside to NFT (and it not major) is to keep a regular eye on EC and PH and making minor adjustments when needed. I had a bigger problem - my hose kept detaching from the pump and after a long weekend away i came back find all my plants had wilted as they not had any water/feed. Re-attached the pump and within minutes the plants started to rise in front of my eyes. After that i made adjustments to make sure this didnt happen again. I also had a HUGE tank so emptying it was a pain as it took 2 of us to move it. Tanks does need changed once a week - 10 days with fresh solution.