Kratky Method
– is a passive hydroponic technique for growing plants suspended above a reservoir of nutrient-rich water. It is undoubtedly the simplest method of growing plants hydroponically.
Kratky has no air stone or pump. See the illustration to the left.
Kratky pots are basically a container (jar, food grade pail, etc. – see the ones on the left) of nutrient water with a method of supporting the plant. There needs to be enough room between the water and the plant for the roots to get air. I leave about an inch below the peat pod or pool noodle for the roots to get air. I then let the water go down as the roots develop. If the Kratky method isn’t working for you, add a pump and air stone. This transforms it into a Deep Water Culture (DWC) system. I use DWC systems on five gallon pails to grow tomatoes.