Importance of water flow rate in controlling water quality processes in marine and freshwater fish ponds

Fish culture systems can be categorized on the basis of flow rate into three types, low, intermediate and high flow, each controlled by different basic biogeochemical processes. Low flow rate ponds operate like algal batch cultures, and the water quality problems manifest themselves as growth inhibition followed in extreme cases by mass mortality. Intermediate flow rate fish ponds operate like contaminated chemostats. They are subject to occasional phytoplankton crashes due to microbial grazing, and the resultant chemical changes can cause mass mortalities of fish. High flow rate systems generally do not reach water quality but biological limits. They may result in significant pollution downstream. Subdivision of fish ponds on the basis of water flow rate enables one to predict the most promising types of biotechnology to solve present and future problems. -from Authors