Aquaponics offers a promising solution for food security in urban areas where agricultural land is rapidly being repurposed. However, its wider use is limited by the high cost of commercial fish feed. Consequently, many aquaponic operators are exploring alternative and less expensive feed options. The major challenge in aquaponics is identifying fish feeds that not only promote healthy fish growth but also enrich the water with nutrients essential for plant development. Since fish feed is the main source of nutrients for both fish and plants in this system, it is important to understand how different feeds affect the whole systems performance. This study addresses this need by comprising the effect of two fish feed sources- biogas slurry and commercial market feed on the growth of Tilapia(Oreochromis mossambicus) and the nutrient quality of water in aquaponic system. The experiment was conducted over a period of two months from 01 August 2024 to 30 September 2024, using a controlled aquaponic setup. Two groups of Tilapiawere maintained: one fed with biogas slurry-based feed and the other with standard commercial feed. Growth performance, water quality parameters, and nutrient levels were regularly monitored. Result showed that fish fed with biogas slurry exhibited slower growth (0.14 g/day) compared to those given market feed (0.43 g/day), indicating that biogas slurry in its current form does not sufficiently meet the nutritional needs of fish. Beside the reduced growth, water quality parameters, including temperature (24-27℃) pH (6.8-7.5), dissolved oxygen (>5 mg/L), and ammonia (<0.2 mg/L), nitrite (0.25-0.50 ppm), nitrate (5.0 ppm) remained within acceptable limits in both systems, confirming that biogas slurry does not negatively impact the aquatic environment. This finding emphasizes a critical need for the development of alternative fish feeds in aquaponics that are nutrient rich and balanced to support optimal health and productivity of both fish and plants. Further research is essential to formulate such feeds, which would enhance the sustainability and efficiency of aquaponic systems.
