Aquaculture America 2020

February 9 - 12, 2020

Honolulu, Hawaii

EFFECT OF SETTLING CHAMBER FLOW RATE ON WATER QUALITY DYNAMICS IN A HYBRID STRIPED BASS BIOFLOC TECHNOLOGY PRODUCTION SYSTEM

 
Bartholomew W. Green* ,  Candis L. Ray
 
 United States Department of Agriculture, Agricultural Research Service
Harry K. Dupree Stuttgart National Aquaculture Research Center
Stuttgart, AR 72160-1050
bart.green@usda.gov
 

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.