The impact of mycofiltration on water quality parameters was examined in the Tarai region of Uttarakhand located at the coordinates of 28°58′ N, 79°25′ E and 252 m asl. The experiment was conducted from November 2018 to April 2019 in circular fiberglassreinforced plastic tanks (water volume 4000 L) with seven duplicate treatments having different filtration rates, namely control, T0 (without filtration); T1 (333 L h−1 through mushroom spent bag), T1' (333 L h−1 through RAS system), T2 (167 L h−1 through mushroom spent bag), T2' (167 L h−1 through recirculated aquaculture system (RAS) system), T3 (83 L h−1 through mushroom spent bag), and T3' (83 L h−1 through RAS system) and different water quality parameters, namely physicochemical, heavy metals, and microbial load were analyzed regularly. Each tank was stocked with 100 number of healthy fingerlings of Ctenopharyngodon idella, Labeo rohita and Cyprinus carpio haematopterus at the rate of 25 fingerlings/m3 in the ratio 3.5:3.5:3.0 and average weight of 20 ± 0.5, 10 ± 0.3 and 10 ± 0.5 g, respectively. The fingerlings were fed daily with 28% crude protein floating feed at the rate of 3–5% body weight. During the experimental period, a lot of improvement was recorded in water quality parameters and microbial loads. The results of the present experiment show that mycofiltration is a better technique for water quality improvement in the fish culture system. The details of the experimental results are described further in the paper.