Effects of Pond Water Quality Indicators on Fish Body Weight Gain and Their Optimal Standarts

This study investigates the correlation between hydrochemical parameters and the body weight gain of yearling common carp (Cyprinus carpio) in ponds with different stocking densities (5,000 and 10,000 fish/ha) during the summer rearing season. The research results demonstrate that maximum weight gain occurs under environmental conditions where ammonia levels range from 0.05 to 0.07 mg/L, dissolved oxygen is at least 4.5–5.5 mg/L, water temperature stays between 20.7 and 25.3 °C, and water hardness is maintained at 3.0 mEq/L. Furthermore, the findings indicate that increasing water temperatures combined with decreasing water hardness exacerbate the toxic effects of free ammonia. These results highlight the importance of monitoring the hydrochemistry of intensive aquaculture systems in order to optimise fish growth and health.