Independent guide · Updated 2026-09-20
Aquarium filtration
Biological, mechanical and chemical filtration selected around livestock, tank volume and maintenance capacity.
Freshwater fishMarine fishAquatic amphibians
What to look for
- Biological capacity
- Media must support enough beneficial bacteria for the aquarium’s actual bioload.
- Flow
- Turnover and current should suit the species rather than chasing a single litres-per-hour target.
- Service access
- A filter that is easy to maintain is more likely to be maintained safely.
Sizing and fit
Use manufacturer flow as a starting point, then account for media, head height, stocking and species that need gentle flow.
Safety checks
- Protect intakes for fry, shrimp and axolotls.
- Keep filter media wet during short maintenance.
- Never replace all mature biological media at once.
Cleaning and maintenance
Rinse mechanical media in removed aquarium water and service components on a staggered schedule without sterilising the biofilter.