Tanks were filled with water from the nearby brackishwater source. The fine mesh filter bag was used to prevent entry of unwanted materials and suspended particles in to the tanks. Two aeration pipes with air stones and regulators with 7.5 m3 air tank−1 min−1 diffusing capacity were provided in each tank to meet the oxygen demand and proper mixing of floc. As an inoculum, 10 L water with bacterial floc developed in a separate tank was added to each tank.