A SIMULATIVE STUDY OF THE EFFECT OF FISH FEEDS PATTERNS ON THE PHYSIOCHEMICAL QUALITIES OF FISH POHD WATER

Aquaculture is one of the fastest-growing food production sectors globally, and its sustainability depends heavily on maintaining optimal water quality. Poorly balanced feeds or excessive feeding introduce significant organic and nutrient loads into pond ecosystems, accelerating water quality deterioration. This study investigated how different fish feed sizes (2 mm, 3 mm, and 9mm pellets) and their proximate compositions influence pond water quality over a five-day period. Proximate analysis revealed notable variations among the feeds: moisture content exceeded FAO limits (2 mm = 11.3%, 3 mm = 15.2%, 9 mm = 23%), crude fibre ranged from 5.0–12.5%, and the finisher feed contained the highest ash (14%) and protein (32.01%). These compositional differences suggested varying potentials for nutrient leaching and organic loading. Water quality parameters demonstrated clear feed-dependent trends. pH values, although fluctuating, were generally lower than the FAO recommended 6.5–9.0 range, with recorded values spanning 3.4–6.8, reflecting acidification linked to organic decomposition and nitrogenous waste accumulation. Electrical conductivity (EC) increased markedly across treatments, with values reaching as high as 7947 µS/cm, far above the recommended 100–2000 µS/cm range, indicating rapid ionic enrichment from mineral and protein leaching. Heavy metal analysis showed repeated detections of lead (Pb) and cadmium (Cd) at 0.01 mg/L, particularly in 3 mm and 9 mm feeds, matching FAO’s maximum permissible limits and signalling potential long-term risks of bioaccumulation. Major water quality indicators also showed progressive deterioration. Total Dissolved Solids (TDS) exceeded 4000 ppm in several treatments, while Total Suspended Solids (TSS) rose daily despite remaining within international guidelines. Dissolved Oxygen (DO) declined rapidly, falling below the safe threshold of 5 mg/L by Day 1 and reaching complete depletion by Day 5 in some ponds. Concurrently, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) increased sharply, exceeding recommended limits by more than ten-fold, driven by microbial activity and excessive organic matter decomposition. Overall, the study demonstrates that feed characteristics—particularly excessive moisture, high protein, and elevated ash contents—combined with feeding intensity, significantly accelerate water quality decline. While nutrient-rich feeds are essential for fish growth, improper management can destabilize pond ecosystems through acidification, mineral accumulation, oxygen depletion, and heavy-metal introduction. Sustainable aquaculture therefore requires not only balanced feed formulation but also controlled feeding practices, continuous monitoring of key water parameters, and the integration of aeration or water-exchange strategies to prevent environmental stress and ensure fish survival.