Activated EM・1 is added to the water treatment pond where water drained from the cultivation is collected. They also use other microbial materials in the water storage pond where seawater is treated before going into the cultivation ponds. The facility is fully equipped with concrete ponds totally covered with plastic canvas bottom and steel truss and black mesh over the ponds to prevent the attack from birds. They also have sludge treatment equipment to withdraw sludge from ponds and a water circulation system. Water quality is carefully checked to prevent the infection of virus and disease measuring pH, alkalinity, salinity, number of Vibrio, etc.