Abstract: An animal habitat arrangeable in a vertical or a horizontal orientation comprising a rectangular enclosure having four side-walls and two opposing end-walls, wherein the four side-walls are joined to a frame at a first end of the enclosure; and the two opposing end-walls comprise a first end-wall and a second-end wall; wherein the first end-wall is releasably connectable to the frame, positionable within the frame in a plurality of orientations and provides an end-wall door with access to an interior of the rectangular enclosure; wherein at least one of the side-walls provides a side-wall door with access to the interior of the rectangular enclosure and has a hinge position which is changeable along opposite side-walls of the enclosure.

Abstract: Disclosed herein are wedge-shaped filter cartridges having a maximized upstream surface area. The filter cartridges are modular and may be stacked in a filter cartridge system.

Abstract: Disclosed are filter assemblies for an aquarium tank. The disclosed assemblies include a filter basket assembly in which one or more filter baskets are connected, either directly or indirectly, to a filter pump basket. The filter pump basket typically is located upstream of the one or more filter baskets and pumps water upwards through the filter basket assembly.

Abstract: An animal housing assembly includes a cage coupled to a base assembly to provide an enclosure for one or more animals to be kept in captivity. The cage is collapsible such that the cage may transition from an expanded state, wherein the cage may cooperate with the base assembly to form an enclosure for an animal, to a collapsed state, wherein portions of the cage may fold into one another into a compact condition. The base assembly may transition from an assembled state, wherein first and second base members are releasably coupled to one another to form the base assembly, to a disassembled state, wherein the first and second base members are separated from one another, thereby allowing a more compact condition.