Growth Inhibition of Algae in Aquaculture Fishponds Using Banana Peel Powder: A Mesocosm Experiment

Cyanobacterial blooms and algal problems in aquaculture fish-ponds have become a significant concern for fish farmers due to the resultant decline in fish production. While numerous studies have been conducted globally on cyanobacterial blooms in oceans and lakes, relatively few have focused on the inhibition of algal biomass affecting aquaculture fish ponds. This study evaluated the potential of banana peel ashes and potassium sulphate to inhibit algal growth in fish ponds through a six-week mesocosm experiment using varying ash concentrations (i.e., 2, 4, 6, 8, 10 g·L−1). Differences among treatments in nutrient variables (nitrates, ammonium, and phosphates) were analyzed at the conclusion of the experiment. Factorial repeated measures ANOVA was employed to assess significant experimental differences in physicochemical variables across the study weeks (i.e., 1–6 weeks), treatments (three levels, including controls), and ash concentrations. Additionally, algal growth inhibition was assessed by measuring chlorophyll-a concentration over the six-week period. Banana peel ashes exhibited significantly greater efficacy in inhibiting algal growth compared to potassium sulphate, with the exception of the controls. However, no clear patterns were observed on nutrient dynamics throughout the experiment. The study demonstrated that banana peel ashes were more effective in inhibiting algal biomass compared to potassium sulphate, while physicochemical variables remained largely unchanged from the start to the end of the experiment. Given the efficacy of banana peel ashes as an inhibitor in this study, further research is recommended to investigate their potential impacts on fish within the ponds.