External biological aquarium filter

Claim 1

An aquarium filter assembly for installation externally of an aquarium tank, comprising: a filter receptacle; separation means within said receptacle for providing in said receptacle a filter chamber beneath said separation means and a clean water chamber above said separation means; said chambers being in fluid flow communication from said filter chamber up through said separation means to said clean water chamber; an inlet port provided in said receptacle in communication with said filter chamber; siphon tube means coupled to said inlet port for a siphon flow of contaminated water from the aquarium tank to said filter chamber; conduit means in communication with said clean water chamber for supplying clean water from said clean water chamber to the aquarium tank; said separation means including a filtering foam material; support means disposed in said receptacle for supporting said filtering material; said receptacle including an elongated closed container; an outlet port provided in said receptacle in communication with said clean water chamber, said conduit means being coupled to said outlet port; said closed container including a top wall, a bottom wall, side walls, and end walls; said inlet port being disposed adjacent to one of said end walls and said outlet port being disposed adjacent to the other end wall; said support means including a first set of elongated ribs extending downwardly from said top wall to provide first elongated rib edges spaced from said bottom wall, and a second set of elongated ribs extending upwardly from said bottom wall to provide second elongated rib edges spaced from said top wall; said first elongated rib edges being spaced from said second elongated rib edges to define therebetween a channel through said receptacle for receiving therein said filtering foam material; said first and second elongated rib edges engaging said filtering foam material to retain said filtering foam material in said channel; and a space between said channel and said top wall defining said clean water chamber, and an opposing space between said channel and said bottom wall defining said filter chamber.