Abstract: 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 nitrifying 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.

Abstract: In the disclosed aquarium system, the aquarium water is purified in a biological/mechanical external filtration means which can also include chemical adsorption elements, if desired. The filtration means typically comprises (a) a pre-filtration zone, containing a relatively "coarse" filter element (e.g. with a pore size greater than 100 microns), and (b) a parallel flow zone containing a "fine" filter element (e.g. with a pore size less than 100 microns) and at least one cultured filter element. The culture of the cultured filtered element typically contains nitrifying bacteria, which help keep the free ammonia concentration in the aquarium system at a low, nontoxic level or even negligible level. The "fine" filter element in parallel with the cultured filter element permits high flow rates through the system and removes fine detritus.