In this experiment, the physiochemical characterization of biodiesel produced from chlorella vulgaris cultured from fish wastewater from aquaponics systems was examined in relation to its water parameters. This effluent was collected from a biofilter that was connected to a fish tank used for culturing chlorella vulgaris; these parameters include electrical conductivity, total dissolved solids, nitrate nitrogen concentration, and pH The algae cultured in a 10-litre photobioreactor produced 30g of wet biomass, and 1.35g of biodiesel was produced using direct transesterification. FTIR physio characterization reveals ester formation at a wavelength of 1743 cm1. The physical properties of the diesel were tested and compared with Indian biodiesel standards. The diesel has a good flash point of 132 and a calorific value of 901 kJ/kg.