Diurnal dynamics of water quality parameters in an aquaculture system based on recirculating green water technology

Recirculating greenwater aquaculture technology is an appropriate method for producing commercial quantities of tilapia in areas where water is scarce. Greenwater systems achieve better fish production, more than 90% water recycling and nutrient utilization. This study was designed to address the diurnal dynamics of certain water quality parameters in greenwater system. Culture tanks were stocked at a density of 40 fish/m³ with mixed-sex Nile tilapia, Oreochromis niloticus fingerlings and fed ad libitum with floating pellets containing 34% protein. The water temperature was kept 28±1°C, aeration was provided and sludge was collected twice daily. Values of critical chemical parameters in the water were found to be well within the acceptable limits based on diurnal water sampling.