These organic hydroponic lettuces are growing in small net pots that are suspended above the water level by a fixed raft. When the water level rises and falls the roots are submerged and then aerated. That’s what we call the ALT method. With a fixed bed and a fluctuating water level the deep water culture becomes our Air Layer Technique. By intermittently exposing the roots to ambient air the roots get oxygenated without water aeration pumps.
In this video the were eating roots of the basil plants. Once the fish was removed the plant roots and growth improved.