Quiet, convenient canister filters are inconspicuously located under your aquarium (typically in the stand). Most canister filters are customizable, and can hold a large amount of media (mechanical, chemical, and biological) in varying combinations. Some examples are included in the table below. Because they are customizable, you have maximum flexibility in choosing the predominant type, and amount of media to achieve your desired end result.
If your fish produce excessive amounts of waste, incorporate a large amount of mechanical media (filter pads of varying coarseness) to effectively remove waste from the water.
If your fish require sparkling water with stable, consistent parameters, use larger amounts of chemical media (carbons and resins).
If your fish consistently produce very high levels of ammonia, which require daily control, make biological media (such as ceramic rings and sponges) your predominant media.
Media is basically interchangeable between canister filters. However, when using any fine media, make sure it is in a media bag, or it may enter and destroy the filter's impeller.
Canister filter/aquarium size recommendations are often given in a range. The low end of the range indicates the maximum aquarium size effectively filtered when the aquarium contains large or high numbers of saltwater or freshwater fish. The high end of the range indicates maximum aquarium size effectively filtered when the aquarium has a small population of fish and a low bio load.