PHYSICOCHEMICAL ASSESSMENT OF WATER SAMPLES

This study assessed the physicochemical properties of water collected from the bottom of aquaculture tanks at the TETFund Centre for Aquaculture and Food Technology, University of Benin. The objective was to evaluate the suitability of the water for aquaculture and identify parameters that could affect fish growth and survival. Water samples were collected from Tank 5 and Tank 6 and analysed for twenty key physicochemical parameters, including pH, electrical conductivity, total dissolved solids, turbidity, suspended solids, dissolved oxygen (DO), biochemical oxygen demand (BOD), hardness, chloride, alkalinity, phosphate, nitrate, ammonium, calcium, magnesium, and selected heavy metals (iron, lead, zinc, chromium, and cadmium). The results were compared with Federal Ministry of Environment (FMEnv) permissible limits for aquaculture water quality. Findings revealed that parameters such as pH, electrical conductivity, hardness, chloride, phosphate, and nitrate were within acceptable limits, indicating general water suitability for aquaculture. However, DO, BOD, turbidity, ammonium, iron, and lead exceeded permissible thresholds, suggesting organic pollution, oxygen depletion, and possible metal contamination. These deviations are likely caused by inadequate aeration, accumulation of feed residues, and sediment deposition at the tank bottom. The study concludes that although the tanks provide a controlled environment conducive to fish culture, poor water circulation and organic waste buildup pose challenges to optimal production. It recommends regular water renewal, installation of aeration systems, and continuous monitoring of physicochemical parameters to maintain sustainable and productive aquaculture operations.