Enhancing water quality and growth of Asian Redtail Catfish <i>Hemibagrus nemurus</i> using nanobubble oxygenation and a recirculating aquaculture system

ABSTRACT Objective This study was designed to evaluate the effect of using nanobubble oxygenation and a recirculating aquaculture system on water quality, growth performance, survival, and hematological parameters in Asian Redtail Catfish Hemibagrus nemurus. Methods The evaluation was conducted for 56 d using a completely randomized design with one factor, four treatment levels, and three replications. The treatments included P0 (stone aerator), P1 (recirculating aquaculture system), P2 (nanobubble oxygenation), and P3 (nanobubble oxygenation + recirculating aquaculture system). Results The best results were observed in P3, which produced an average absolute weight, absolute length, specific growth rate, feed efficiency, feed conversion ratio, and survival rate of 8.63 ± 0.07 g, 6.02 ± 0.18 cm, 2.46 ± 0.03%/d, 62.33 ± 1.05%, 1.60 ± 0.03, and 94.64 ± 1.75%, respectively. The water quality in this treatment was within the optimal limits for growth and survival, with temperatures ranging from 26.2°C to 28.4°C, pH levels from 6.3 to 8.0, ammonia concentrations from 0.04 to 0.88 mg/L, nitrite levels from 0.07 to 14.24 mg/L, nitrate levels from 0.05 to 14.01 mg/L, and CO2 concentrations from 2.5 to 12.5 mg/L. Conclusions The results showed the potential benefits of integrating nanobubble oxygenation and a recirculating aquaculture system in an aquaculture system for improving the growth and survival of Asian Redtail Catfish. The application of nanobubble oxygenation combined with a recirculating aquaculture system significantly improved the growth, survival, feed efficiency, health (hematologically and histologically), and water quality parameters that were measured, suggesting the potential effectiveness of this aquaculture technology.