Fluval Nitrate Cartridge G6
Suits tanks
300–600 L
Water type
Freshwater
Fits
Fluval G6
Part no.
A422
Fluval Nitrate Cartridge G6
A drop-in nitrate scrubber sized for the larger Fluval G6 filter. The Fluval Nitrate Cartridge G6 (Fluval part A422) is chemical filter media pre-loaded into a cartridge that seats directly into the G6 canister, rated to remove up to 24,000 mg of nitrate ion from freshwater aquariums — roughly double the capacity of the G3's equivalent cartridge, to match the G6's larger media volume.
Key features
- Purpose-built for the Fluval G6 — drops straight into the G6's media stack; no repacking of loose resin.
- Removes up to 24,000 mg of nitrate ion — sized for the G6's larger 300–600 L tank range and aimed at keeping freshwater nitrate below the commonly recommended 20 mg/L.
- No cycle disruption — chemical media only; doesn't touch the biological or mechanical stages running alongside it in the G6.
Specifications
| Spec | Value |
|---|---|
| Fits | Fluval G6 Advanced Filtration System |
| Manufacturer part number | A422 |
| Nitrate removal capacity | Up to 24,000 mg nitrate ion (freshwater) |
| Media type | Chemical (nitrate-adsorbing resin) |
| Target parameter | Keep freshwater nitrate below approximately 20 mg/L |
Suitable for, and not suitable for
- Suitable for Fluval G6 filters running on freshwater aquariums with elevated nitrate.
- Not suitable as a substitute for regular water changes — it's rated as a supplementary reducer, not a replacement for husbandry.
- Not rated by Fluval for marine/reef nitrate control at this capacity — treat it as a freshwater-specific cartridge.
Care and maintenance
Fluval doesn't publish a fixed replacement calendar for this cartridge — capacity depends on your tank's nitrate load. Test freshwater nitrate periodically; once levels stop falling, or the cartridge has been running several months under normal freshwater bioload, replace it. If you're using it as a one-off fix for a nitrate spike rather than ongoing control, it can be removed once levels have settled back down.
Warranty and delivery
Standard parcel delivery. As a chemical filter media, it's a consumable and isn't covered by a separate warranty term beyond your rights under Australian Consumer Law.
Common questions
Does this fit the Fluval G3?
No — the G3 uses its own smaller nitrate cartridge (Fluval A421), rated at 13,000 mg to match the G3's smaller media volume.
Will it affect my biological filtration?
No — this is a chemical media cartridge that sits alongside the G6's biological and mechanical stages without disrupting them.
Can I use it in a marine tank?
Fluval rates this cartridge specifically for freshwater nitrate removal; we don't have a published marine capacity figure for it.
