Untreated fish is led through a delousing line and to AKVA FLS Weighing and Counting System for optimal control and documentation. The treatment happens in a closed low-pressure system where the fish is treated with seawater. The treatment pressure is only 0.2-0.8 bar and the treatment time is only 2 seconds. The fish are separated from the treatment water as they are delivered to the pen. The treatment water is sucked back and filtered on board.