Product guide

Fluval U4 Filter Media Value Pack, model A350

Fluval U4 Filter Media Value Pack A350 is a replacement-media set for Fluval U Series internal aquarium filters. It combines biological Biomax media, Bio-Foam for trapping debris and a Poly-Carb cartridge with polyester and activated carbon layers. The listing says one pack provides media for up to six months.

At a glance

Biomax is described as supporting beneficial bacteria growth and the natural nitrogen cycle.
Bio-Foam traps larger waste and debris while maintaining water flow, according to the listing.
The Poly-Carb cartridge combines a polyester particle-trapping layer with activated carbon.

Price

£12.99Save 38%

Reference price: ~~£20.99~~

Price checked: 13 Nov 2026

View offer

Often bought together

FLUVAL U4 Internal Filter, 240 Litre

£63.95

Fluval U4 Internal Filter Foam Pad

£6.19

Pros and cons

Pros

Includes biological, foam and combined polyester-carbon media for routine Fluval U filter maintenance.
Media types have distinct listed roles, from catching debris to supporting beneficial bacteria.

Technical specifications

13 specifications

Compatibility and use
Designed for	Fluval U internal aquarium filters
Specific uses	Indoor
Claimed media coverage	up to 6 months

Media types and functions
Biological media	Biomax
Foam media	Bio-foam
Combined cartridge	Poly-Carb
Polyester layer	captures fine particles
Activated carbon layer	removes toxins, discolourations and odours

Dimensions and installation
Weight listed	210 g
Package dimensions	27.4 x 12.9 x 8.3 cm; 210 g
Quantity	1

Power
Batteries required	No

Identification
Model number	A350

What to know before buying

The claimed media coverage is up to six months, not a guaranteed replacement interval. The listing advises replacing media regularly, so actual timing may depend on aquarium conditions and use.

Who is it for?

A good fit for

Fluval U Series internal-filter owners seeking a replacement set with biological, foam and carbon filtration media.
Aquarium keepers who prefer one pack containing several media types rather than purchasing each separately.

Less suited to

Owners of filters outside the Fluval U Series unless compatibility is confirmed.
Buyers seeking the internal filter itself rather than replacement media.

Customer reviews on Amazon

4.6 / 5 · 161 ratings

5 stars77%77%
4 stars17%17%
3 stars2%2%
2 stars1%1%
1 star3%3%

Customer feedback describes the media pack as good quality and good value. That may matter to buyers looking for a consolidated replacement set, though customer impressions do not establish filtration performance or the claimed replacement period.

Positive themes

Customers describe the pack as good quality.
Customers consider it good value for money.

Frequently asked questions

Which filters is this media pack designed for?

The listing identifies it for Fluval U Series internal aquarium filters. Confirm the exact filter model before ordering if compatibility is uncertain.

What media types are included?

The listing describes Biomax, Bio-Foam and a Poly-Carb cartridge with polyester and activated carbon layers.

How long does one pack last?

The listing claims media for up to six months and also advises regular replacement. Treat six months as a maximum claim, not a fixed schedule.

Does this pack include a Fluval U4 filter?

No filter is listed as a pack component. The product is described as replacement filter media.