Cyanobacterial blooms are a major problem for aquatic ecosystems and fish farming activities, affecting water quality and the health of organisms. This paper compares the effectiveness of three control methods applied in experimental fish ponds: chemical treatment with copper sulphate, treatment with hydrogen peroxide, and an ecological method based on the use of barley straw. Over a period of eight weeks (June-August 2025), the physical and chemical indicators of the water, the concentration of chlorophyll a, and the density of cyanobacteria were analysed in four ponds with a history of algal blooms, namely cyanobacteria. The results show that hydrogen peroxide (5 mg/l) significantly reduced cyanobacterial biomass (p<0.05) without major negative effects on other parameters, while copper sulphate had a rapid but temporary effect. Barley straw showed moderate effectiveness, with slow but favorable effects on maintaining ecological balance.