Abstract: An apparatus is disclosed for removing organic waste from a stream of water and for growing Tubifex worms, Chironomidae larvae, infusoria and other like organisms. The apparatus comprises a plurality of pans with each successive pan displaced below the preceding pan so that water is allowed to run therethrough. Dividers are positioned within the pans to entenuate the channel in which the water flows. The organisms are added to collect organic waste, digest it and thereby clear the water. After the organisms multiply to the extent of having a population in excess of the numbers optimal for filtering, the excess is removed from the pans and used as a source of protein for animal feeding.