NFT (nutrient flow technique) . Basicly there is a constant flow of water (nutes) pumped from a ?? gallon container into a slightly sloped tray, the rockwool cubes are sat on the tray and the water flows across the bottom of the tray constently feeding .Weed seems to love this grow method if you havent tried NFT do so you wont be dissapointed :thumbsup: :stoned: