Abstract: A system for controlling a flow of water out of a container in a manner to prevent the generation of noise as an incident to the outflow and to permit adjustment of the water level in the container, the container being a component of apparatus for maintaining water at a desired level in an enclosure. The system basically includes: an outflow conduit defining an outlet flow path via which water flows downwardly out of the container, the conduit having an upper end located within the container and having an inlet opening; a cap overlying the inlet opening and defining with the conduit upper end an annular flow path via which water flows to the inlet opening; and a vent tube extending vertically downwardly through the cap and into the conduit to establish an air flow path between a region above water in the container and a region within the conduit.

Abstract: A biological filter for treating water in an aquatic system, composed of a porous water absorbing body of material adapted for rotation, and a member for supplying water to the body to be absorbed by a portion of the body so as to cause the body to rotate, wherein the member for supplying water to the body is composed of a receptacle located above the water absorbing body, the receptacle defining a water holding volume having a bottom, and the bottom being provided with at least one opening via which water flows out of the volume and onto the water absorbing body under the force of gravity.

Abstract: An aquatic filter system having a rotatably mounted cylindrical filter body. The cylindrical filter body is formed by a water absorbing mass of material. Water applied to one side of the filter body unbalances the filter body which causes the filter body to rotate. As a result of the rotational movement, at least a portion of the filter body is alternately exposed to the water and the atmosphere to foster the growth of aerobic bacteria on the surfaces of the filter body.

Abstract: An improved aquarium pump for use with an aquarium filter which includes a filter box, a rotating biological filter element and a spray bar, the pump supplying water to the rotating biological filter element and the spray bar. The pump may include a pair of impellers for supplying water to the filter box and the spray bar, respectively.

Abstract: An apparatus for expelling gas from within a sealed container. The apparatus may include a device for collecting gas in a predetermined area within the container as well as a device for drawing the gas out of the predetermined area and for directing the gas into the inlet of a pump. The apparatus eliminates problems related to the buildup of gas within the container such as water noise and vapor lock.

Abstract: An aquarium filter system having a rotatably mounted filter body. The filter body is structured such that when mounted with a portion of the filter body submerged in moving water, rotational movement is imparted to the filter body by the moving water. As a result of the rotational movement, at least a portion of the filter body is alternately exposed to the water and the atmosphere. This fosters the growth of aerobic bacteria on the surface of the filter body. The aerobic bacteria reduces the level of toxins within the aquarium water.

Abstract: An improved canister-type aquarium filter design which includes, in various combinations, a motor which is contained within the canister, a discharge tube arranged approximately along the longitudinal axis of the canister, a pump section from which water exits from the top, a cover securing device which applies force to the top of the cover, a clamp arrangement for securing tubes to ports on the cover, and an adjustable mounting system for mounting the filter to an aquarium frame. The improved design provides easy access to the filter cartridge, improves efficiency, and eliminates the need for flexible hoses traditionally used to connect the filter to an aquarium.