An eight weeks experiment was conducted to investigate the effect of borehole water treated with Bio-disc on water quality and the growth performance of Clarias gariepinus fingerlings. The fish were fed a commercial diet containing 40% crude protein twice daily in plastic aquaria tanks (50cm × 40 cm × 30 cm) fill with 20 litres of water. There were twenty-five fish (average weight of 2.40g) stocked in each aquarium. The study was conducted in four different experiments (D1 – D4) with three replicates. The water in the tanks was changed with pre-conditioned borehole water every week subject to each experimental need. The water in the control (D1) was changed once in a week without treatment with Bio-disc, the water in D2 was energized with Bio-disc once in a week. The water in D3 was energized twice in a week while water in D4 was energized thrice in a week with Bio-disc. The water for the experiment was energized by running the water on the surface of the Bio-disc into the experimental tanks for a period between 30 – 60 minutes. The best growth performance was achieved in D3 which recorded the highest weight gain (27.64 ±0.70g) and specific growth rate (4.49±0.05 g/d). The D2 and D4 were significantly higher than the control experiment (D1) (p < 0.05). The values obtained are much higher in D3 than others, which show that treatment of water with Bio-disc twice a week proves to be more effective in the growth performance of the fish. However, treatment of water with Bio-disc has no effect on the water quality parameters but improves the water condition resulting in higher growth performances of the fish.

Keywords: Bio-disc, water quality parameters, Clarias gariepinus, growth performance.