Aquarium filter

An externally-mounted aquarium filter assembly comprising:

• a tank having means to support said tank on a wall of an aquarium;
• partition means disposed in said tank for dividing the interior of said tank into a pre-filter chamber and a post-filter chamber, said partition means comprising a raised partition base plate and a first and second pair of generally upstanding, spaced-apart track means, each pair of which define an opening therebetween for the receipt of a filter cartridge, which openings further establish communication between said chambers, said pre-filter chamber occupying the tank space defined between said track means and said post-filter chamber occupying the remaining tank space outwardly of said track means with said partition plate defining a passageway therebelow for establishing communication between said remaining tank space disposed outwardly of said track means;
• a pair of filter cartridges, each of which is independently removably mounted within said openings of said track means so that water passing from said pre-filter chamber to said post-filter chamber passes through said filter cartridges for trapping particulate matter in said water;
• inlet means mounted on said tank for introducing water from the aquarium to said pre-filter chamber;
• and
• outlet means mounted on said tank for returning water from said post filter chamber to the aquarium.