Abstract: An aquarium filter-aerator device having a substantially pyramidic construction with water inlets on all sides that operates on an air-induced water flow principle anywhere along the bottom of an aquarium. The filter-aerator has an inner construction that defines a pre-filter chamber which accumulates impurities and a post-filter chamber for aerating the purified aquarium water. The particular construction and disposition of the filter-aerator facilitates the forming of a plurality of directional water currents to sweep aquarium impurities into the filter-aerator.

Abstract: A unique cover is provided for connecting an aquarium to provide effective regulation of the environment therein whereby the structure may serve as a terrarium. The cover includes a cover member which is adapted to overlie a typical aquarium tank or vessel, and a continuous frame support member extending around the periphery of the cover member and adapted to abut with the tank when the cover is in place. The cover member is provided with at least one opening, into which ventilation control pieces are positioned. The ventilating pieces may be selectively adjusted to control the ventilation of the aquarium or terrarium. The support member, being continuous, provides a substantially moisture impermeable seal with the tank when the cover is in position.