Facts on Aquarium Canister Filters

Aquarium owners have several options when choosing filtration. Canister filter systems are designed to provide powerful, thorough cleaning and the flexibility to adapt to different needs.

  1. Description

    • A canister filter has a sectioned container. Typically, the sections hold sponge, activated carbon and filter media such as ceramic "noodles" (short, thin ceramic pieces) or "bio-balls" (texturized plastic balls). The unit has a built-in motor that draws water in and through the sections and then returns it to the tank.

    Function

    • Canister filters provide filtration three ways: The filter media and sponge trap pieces of debris (mechanical), the carbon neutralizes harmful gases and chemicals (chemical) and the various parts support colonies of bacteria that break down waste (biological).

    Pros

    • Canister filters turn over large amounts of water quickly--often your tank's entire volume several times an hour. This makes them an excellent choice for large tanks, fish that produce a lot of waste, and species that require very clean water. Canisters can be customized. They allow you to position the filter tubing and unit in different ways, adjust the water flow and use different types of media in the compartments.

    Cons

    • The filter unit can be large, bulky and difficult to clean. Canister filters are usually more expensive than other varieties.

    Warning

    • Because canister filters process water rapidly, waste matter can build up quickly. Clean them frequently.