Nutriculture GroTank NFT SystemOverview The Nutriculture GroTank Nutrient Film Technique (NFT) System oxygenates your plants' roots. The plants are placed in rockwool and benefit from increased access to oxygen. The system constantly pumps nutrient solution to the roots. The GroTank is also known as a pure hydroponic solution because it comprises virtually no medium. The rockwool blocks in which your plants started growing is the only grow medium used. The consistent water supply