Effects of solids removal on water quality and channel catfish production in a biofloc technology production system

Total suspended solids control was evaluated in a channel catfish (Ictalurus punctatus) biofloc technology production system. Settling chamber flow rates were 0.9 (LO) or 2.9 (HI) L/min to reduce total suspended solids to 300 mg/L; solids were not removed from control tanks. Channel catfish yields (7.6-8.7 kg/m(3)) were not affected significantly, but control fish were skewed toward smaller size classes. Control treatment channel catfish tolerated 1,410 mg/L total suspended solids without adverse effects. LO- and HI-treatment fillet geosmin concentrations were high enough to be designated as off-flavor. Water quality results suggested that nitrification was affected by solids removal.