Fluval FX4/FX5/FX6 Bio Foam 2 Pack
Pack size
2 pads
Water type
Freshwater + Marine
Fits
FX2, FX4, FX5, FX6
Part no.
A239
Replace every
12 months
Media type
Fine-pore biological and mechanical foam
Fluval FX4/FX5/FX6 Bio Foam 2 Pack
The fine second-stage foam that catches what the first pad lets through. Fluval's Bio-Foam+ (Fluval part A239) is a denser-pored foam sized for the FX2, FX4, FX5 and FX6 canister filters, sold here as a pair so you can rotate media at each service without leaving your filter short a pad.
Inside each pad is a tighter pore structure than the coarse first-stage foam, built to trap the finer particles a first pass misses while giving nitrifying bacteria a large surface area to colonise. It's doing mechanical and biological work in the same piece of foam, which is why Fluval stacks it as the second media stage in the FX range.
Key features
- Genuine Fluval A239 media – sized to seat correctly in the FX-series basket without gaps.
- Dual-stage action – finer mechanical trapping plus a large surface area for beneficial bacteria.
- Sold in pairs – so you can replace one pad at a time and never strip your filter of established bacteria in a single service.
- Fresh and marine safe.
Will it fit my filter?
Fluval part number A239, our SKU FA142. Fits the Fluval FX2, FX4, FX5 and FX6 canister filters. Confirm the model printed on your filter's motor head before ordering – it won't seat in filters outside the FX range.
Specifications
| Pack quantity | 2 pads |
|---|---|
| Genuine part number | A239 |
| Fits | Fluval FX2, FX4, FX5, FX6 |
| Media type | Fine-pore biological and mechanical foam |
| Water type | Freshwater and marine |
Suitable for, and not suitable for
Suitable as the second-stage media in any FX2, FX4, FX5 or FX6 running a standard biological filtration setup. Not a substitute for the coarse first-stage foam block, which handles the larger debris this finer pad would clog on quickly if it worked alone – run both stages together.
Care and maintenance
Fluval's published FX6 maintenance schedule calls for rinsing bio-foam in tank water every 3 months, and replacing roughly half your bio-foam pads once a year rather than the full set at once – which is why it's sold as a 2-pack: replace one pad, keep the other seasoned, then swap the other at the next annual service. Never rinse in tap water or use soap; both kill the bacteria colonising the foam.
Goes well with
Pairs with the Fluval FX4/FX5/FX6 Foam 3 Pack as the coarse first stage, and the Fluval FX4/FX5/FX6 Carbon Pads for chemical polishing.
Warranty and delivery
Covered by Fluval's standard replacement-parts warranty against manufacturing defects, in addition to your rights under Australian Consumer Law. Standard freight.
Common questions
What's the difference between this and the Foam 3 Pack?
This is the finer, second-stage pad (Bio-Foam+, A239); the Foam 3 Pack is the coarser first-stage block (A228). Both run together in a normal FX-series setup.
How often do I replace it?
Rinse every 3 months, and replace roughly half your bio-foam pads once a year – this 2-pack lets you stagger that rather than replacing everything at once.
Can I rinse it in tap water?
No – tap water's chlorine or chloramine kills the bacteria colonising the foam. Rinse in removed tank water only.
Does it fit the FX2?
Yes, Fluval lists this as compatible with the FX2 as well as the FX4, FX5 and FX6.
