Characterization and evaluation of Moringa oleifera seed powder as a flocculating agent in biofloc culture of Clarias magur catfish

Flocculation is key to the performance of biofloc systems, and largely achieved using synthetic flocculants, which are not cost-effective. In this study, we investigate the potential of de-oiled Moringa oleifera seed powder (DMSP) as a natural bio-flocculant in biofloc system to enhance floc formation and water quality. DMSP was prepared through drying, husk removal, grinding, and oil extraction, then characterized for particle size, charge, and surface features. Laboratory tests confirmed strong flocculation efficiency, removing over 90% suspended solids at optimal conditions. A 45-day biofloc trial with catfish, Clarias magur (avg. wt. = 0.36 ± 0.02 g) stocked at 80 individuals per tank revealed that 70 mg L −1 DMSP significantly reduced ammonia and nitrite levels, increased nitrate concentrations, and improved microbial nitrification ( p < 0.05) in the fish culture system. Fish performance in terms of biomass gain, survival, and feed utilization also improved markedly in the same dosage group. These results highlight DMSP as a eco-friendly alternative to synthetic flocculants, offering practical benefits for sustainable aquaculture by improving both system stability and fish productivity.