How often should filter media be replaced?
Written by
Susan Taylor
Reviewed by
Prof. David Walsh, Ph.D.The replacement of filter media is scheduled differently for each application. The mechanical type must be changed frequently when clogged. The chemical type must be changed only once a month before saturation occurs. The biological type must never be completely changed so that the needed bacterial colonies are preserved. The timing of these changes is crucial to prevent water quality issues.
Mechanical Media
- Replace filter floss weekly when discolored
- Swap sponge pads monthly or when flow decreases
- Rinse reusable sponges in tank water during changes
- Never clean with chlorinated tap water
Chemical Media
- Activated carbon: Replace every 3-4 weeks
- Purigen: Regenerate monthly with bleach solution
- Phosphate removers: Change when exhausted
- Monitor water clarity as indicator
Biological Media
- Ceramic rings: Rinse quarterly in tank water
- Bio-balls: Never replace, only gentle rinsing
- Preserve bacteria colonies during maintenance
- Replace only if physically damaged
Different media types serve different purposes and have different schedules of operation. Mechanical media accumulate rubbish, which can make them useless when clogged. The chemical addition media will lose their ability to adsorb once the various types of chemicals have been used. The biological media consists of live bacterial colonies that require preservation. The maintenance schedules laid down will prevent the release of toxins or a crash cycle.
Stagger your maintenance schedules to protect biological filtration. I change the mechanical media weekly when doing the water change. The chemical media is replaced mid-month. The biological media is rinsed well quarterly. This way, you can maintain a consistently high water quality while controlling ammonia spikes. Never change all the media at once.
Allow spare biological filters to colonize in your filter. I use sponge filters alternately in tanks to keep back-up reserves of bacteria. This provides immediate emergency filtration in the event of sudden failures. Regular maintenance gives clear water and lower costs in the long run.
Read the full article: Aquarium Filter Types: Your Essential Guide
