Abstract: An aquarium filter which is positioned within the aquarium tank on top of and in direct contact with a means of support so that the filter is upwardly disposed from the bottom of the aquarium tank to form a fluid chamber between said means and the bottom of the aquarium tank. A section of permeable synthetic filter material interposes a lower filter member and an upper filter member and the whole thereof is encased in a section of synthetic screen material. A conventional pump assembly is provided as a means for recirculating water through the aquarium filter whereby waste material and debris are collected within said filter and eliminated by natural decay. The movement of water through the aquarium filter also causes air bubbles to collect within said filter thus providing a source for continual passive aeration of the aquarium water.