Treatment 2 used a Wave 36 Vortex Filter as the primary solids removal device.The swirl separator had a diameter of 1.0 m and volume of 0.93 m.The base of the swirl separator was situated approximately 46-cm below ground level.Water left the fish production tank throufh a central bottom drain and entered the swirl separator tangentially at its base through a 7.6-cm PVC pipe