<p>Efficient biological and mechanical and/or chemical filtration or purification of the water in an aquatic life support system is achieved with a submerged device through which a high water flow rate is induced by a generally vertical flow of air through the hollow core of one or a plurality of filtration elements. Each filtration element accommodates a high flow rate (e.g. more than 50 gallons per hour) and can contain a viable colony of mitrifying bacteria. The preferred filtration device comprises a base with a plurality of air inlets and air passageways or conduits to the aforementioned hollow core of each filtration element. The base supports and positions the filtration elements. Increased flow rates can be achieved by affixing a hollow tube or conduit to the upper end of the aforementioned hollow core of a filtration element.</p>
