When and How to Clean Your Aquarium Filter

Your filter holds a large share of nitrifying bacteria. Rinse sponge and ceramic media in a bucket of old tank water during a water change — never under the tap with chlorinated water. Replace carbon on a schedule if you use it, but leave bio-media alone unless it is physically falling apart.

If flow drops, clean mechanical floss first. Cleaning every media compartment the same day can mini-cycle the tank.

Space filter maintenance across weeks if you run multiple sponges. Schedule filter rinses in ReefDiary next to water changes so you do not accidentally strip the biofilter the day before adding new fish.