Abstract: A filter system is used in water treatment for removing organic waste from fresh or salt water found in aquariums and culture systems and to facilitate gas exchange between water and atmosphere. The filter includes an air and organic waste laden water mixer, a water-air laden waste separator and an organic waste remover. The mixer is a long tube which has at its top, an inlet pipe that delivers organic waste laden water at high pressure into the tube, and surrounding apertures through which air is drawn. This tube is filled with water-air mixing media such as bioballs and has an outlet opening in the base of the tube which feeds water and waste laden air bubbles into a separator box. The separator box includes a deflector over which the water-air laden organic mix travels. The rising air will pull the organic waste attached to it upward into a foam collector for waste removal. The cleansed or treated water is discharged through a valve beyond the deflector.