Fluval FX4/FX5/FX6 Giant Top Cover Click-fit O-Ring 2 Pack
Water type
Freshwater + Saltwater
Fits
Fluval FX4, Fluval FX5, Fluval FX6
Part no.
A20212
Fluval FX4/FX5/FX6 Giant Top Cover Click-fit O-Ring 2 Pack
Cures the air draw and slow leak at your FX canister's top cover. The Fluval FX4/FX5/FX6 Top Cover Click-Fit O-Ring (genuine Fluval part A20212) is the seal at the top cover connections on the FX4, FX5 and FX6 canister filters. Sold as a genuine Fluval pack of two, it restores a positive, watertight click-fit where a worn O-ring is letting air in or water weep out.
Key features
- Genuine Fluval part A20212 — the manufacturer's own seal, not an aftermarket substitute
- Pack of two click-fit O-rings
- Cures air draw, bubbling and weeping at the top cover fittings
- Quick push-fit replacement — no tools or lubricant required
Specifications
| Spec | Detail |
|---|---|
| Genuine Fluval part number | A20212 |
| Fits | Fluval FX4, FX5, FX6 canister filters |
| Pack contents | 2 click-fit O-rings |
| Fitting type | Push-fit, top cover connection |
| Suitability | Freshwater and saltwater aquariums |
Will it fit my filter?
This is the genuine Fluval O-ring for the top cover click-fit connections on the FX4, FX5 and FX6 canister filters — the fitting is unchanged across all three models, so this suits any age of FX4, FX5 or FX6.
Suitable for, and not suitable for
Suitable where the canister spits bubbles after priming, or weeps at the lid fittings.
Not suitable for the main canister body seal or the motor head gasket — those are different Fluval spare parts.
Care and maintenance
O-rings harden with age and lose their seal well before they visibly perish. If your canister has ever run dry or been left disassembled for an extended period, replace this O-ring as routine maintenance rather than waiting for a leak to appear.
Warranty and delivery
This is a genuine Fluval spare part, covered by Fluval's manufacturer warranty terms in addition to your rights under the Australian Consumer Law. Ships as a small parcel with standard delivery.
Common questions
Why is my filter bubbling after I prime it?
Usually a tired O-ring at the top cover click-fit, letting air draw in at that joint.
How often should I replace it?
Fluval doesn't publish a fixed interval. Replace at the first sign of weeping or bubbling, or after the canister has been left dry for an extended period.
How many O-rings are in the pack?
Two.
Is this a genuine Fluval part?
Yes, genuine Fluval part A20212.
