General Info:

Aquarium filters are marvelous devices, saving aquarists a lot of work as they collect waste products for easier removal. But that “removal” remains the hobbyist’s job, and one that should not be taken lightly.

Nearly all filters, even so-called “biological” filters like undergravels and certain slow-flow canisters, perform “mechanical” filtration; that is, they collect a certain amount of solid waste. Some, like most power filters and fast-flow canisters, are specifically designed to collect such waste efficiently, rather than allow it to accumulate in the aquarium.

But collecting waste is only the beginning, with removal and disposal completing the picture. Is it good enough to just collect garbage in the kitchen wastebasket indefinitely, without ever taking it out to the garbage truck? (Men and teenagers: ask your wives or mothers if not sure about this.) Well, it’s not good enough to simply put a filter on an aquarium, and consider the job done.

For one thing, aquarium filters often double as circulation/aeration devices. As they become clogged with waste products, their flow rates drop or even cease altogether, drastically reducing the amount of dissolved oxygen available for the livestock. In extreme cases, whole tanks full of fish can be lost in a few hours. Under less drastic circumstances, fish can become more prone to disease and overall health and growth can be diminished.

But even if there is adequate circulation from other sources, there’s no good reason to allow filters to become overloaded with waste. Rotting waste in a filtration device fouls the water every bit as much as rotting waste in the aquarium itself. In fact, it can be said that a filter isn’t a filter unless it’s cleaned.