Bottom aquarium filter
A bottom aquarium filter for an aquarium tank which includes a container having an inlet compartment which can receive contaminated water from the tank, and a filtration compartment which converts the contaminated water into decontaminated water. The filtration compartment contains a mass of filtering material with a restraining plate positioned in the filtration compartment to restrain the filtering material within one section thereof while maintaining another section substantially free of such filtration material, thereby providing a flow chamber which couples the inlet compartment to the section containing the filtering material. An air diffuser, attached by tubing to an air compressor located outside the aquarium tank, provides a stream of air bubbles to lift water from the decontaminated water compartment through an air lift tube. In this manner, contaminated water from the tank enters into the inlet compartment and from there passes through the flow chamber into the section containing the filtering material where the contaminated water is substantially decontaminated. The water then leaves together with the air through an outlet in the air lift tube and back into the tank. The flow chamber is also provided with inlets for receiving contaminated water from the aquarium tank. The bottom wall of the filter is provided with a weighted member to prevent the filter from floating up from the bottom of the tank.