treats polluted water by enhancing the amount of oxygen to boost the function of bacterium in decomposing any organic matters in the water, clearing away the cause of deterioration. The aerator has been designed to allow the water to have some contact with the air. Each of its spraying paddles plunges into the water and lets it seep through the holes as the paddles rotate upwards into the air. Such rotation helps add the amount of oxygen and thus purify the water.