A mixotrophic biofloc technology production system is characterized by high stocking and feeding rates. Excretion of metabolized feed stimulates primary and secondary productivity and leads to increased total suspended solids and nitrate-nitrogen concentrations. Published literature suggests that the culture species is impacted negatively at high total suspended solids concentration. Thus, a side-stream settling chamber is activated to maintain a desired total suspended solids concentration . The impact on water quality dynamics of three settling chamber flow rates (retention times) were tested in a hybrid striped bass (Morone chrysops x M. saxatilis ) biofloc technology production system located outdoors. Each of n ine 2.4-m diameter tanks (4.7 m2, 3.6 m3 ) was equipped with a 130-L conical bottom settling chamber into which tank water flowed via air lift pump at 1.5, 3, and 7.2 L/min. Hybrid striped bass (104.9 g/fish) were stocked into tanks at 8.5 fish/m2 (1.16 kg/m3 ) and grown for 125 days. Water quality and production data will be presented and discussed.