Aquarium Filter Foam – 3cm Thick Bio Cotton Sponge
3cm thick aquarium filter foam in white biochemical cotton. Available in four sizes up to 100x50cm so you can cut it to fit your filter chamber.
$14.00 – $21.00Price range: $14.00 through $21.00
Free Shipping
Over $100
30-Day Easy
Returns
Secure Checkout
Over $100
Aquarium Filter Foam – 3cm Thick Bio Cotton Sponge
Filter manufacturers sell replacement sponges cut to their own dimensions, which is why a piece of foam the size of a paperback can cost more than it should. This aquarium filter foam is supplied as a flat sheet instead, 3 cm thick and up to 100 x 50 cm, so you cut it to whatever shape your canister, sump or internal chamber needs. It is biochemical cotton, meaning bacteria colonise it, so it filters mechanically and biologically at the same time.
Why fish keepers choose it
- ✔ 3 cm thick sheet — substantial enough to hold its shape
- ✔ Cut to fit — no paying for a proprietary-shaped sponge
- ✔ Biochemical cotton — hosts the bacteria that process waste
- ✔ Four sizes — up to 100 x 50 cm for larger chambers
- ✔ White, easy to monitor — you can see when it needs rinsing
At a glance
| Thickness | 3 cm |
| Sizes | 100×13.5cm, 100x30cm, 50x50cm, 100x50cm |
| Colour | White |
| Type | Biochemical cotton foam |
| Cleaning | Squeeze in tank water |
Which size do you need?
Measure the chamber your aquarium filter foam has to fill, then add a little extra so the sheet presses against the sides — water should be forced through the foam rather than around it. For a slim internal filter the 100 x 13.5 cm sheet is usually enough; for a large sump or a multi-stage canister, the 100 x 50 cm size gives you more sheets from one piece. Two layers of 3 cm foam can be stacked where a thicker block is needed.
Care
Squeeze the foam out in tank water during water changes rather than rinsing it under the tap, which would kill the bacteria living in it. A white foam makes it obvious when it is clogged, so check it at each change. Replace the sheet once it loses its spring and compresses permanently.
What’s in the box
1 x sheet of aquarium filter foam, 3 cm thick, in your chosen size.
Servicing a filter? Browse our filtration and water equipment, or add the activated carbon media bags for chemical filtration.
For information on aquarium filtration, see the PetMD fish care guide.
| Weight | 14 lbs |
|---|---|
| Dimensions | 10 in |
| Power (W) | None |
| Type | fish |
| Color | White |
| Size | 100cmx13.5cmx3cm, 100x30x3cm, 50x50x3cm, 100x50x3cm |
| Thickness | 3cm |
| Choice | yes |
Frequently Asked Questions
Measure the chamber you need to fill, then choose the sheet that gives you enough material. The 100 x 50 cm option yields the most pieces from one sheet.
Yes, that is the point. Cut slightly oversize so the foam presses against the chamber walls and forces water through it rather than around the edges.
No. This is a 3 cm biochemical sponge that hosts bacteria and can be rinsed and reused. Filter wool is finer, disposable and mainly mechanical.
Squeeze it out in a bucket of tank water during water changes. Rinsing under the tap kills the bacteria living in the foam.
Yes. Two layers of 3 cm foam give you a 6 cm block where a thicker filter pad is needed.
Once the foam stays compressed and stops springing back. Before that, rinsing is usually enough to restore flow.
✔ Heavy glazed ceramic
✔ Non-slip, tip-resistant base
✔ Seven colours available
✔ Does not absorb odours
✔ Rinse-clean surface
• Press the bowl into the bedding so it sits level
• Rinse and refill daily
• Wash with warm soapy water every few days
• Avoid abrasive scourers on the glaze
• Check the rim for chips and replace if cracked
Aquarium Filter Foam – 3cm Thick Bio Cotton Sponge
Filter manufacturers sell replacement sponges cut to their own dimensions, which is why a piece of foam the size of a paperback can cost more than it should. This aquarium filter foam is supplied as a flat sheet instead, 3 cm thick and up to 100 x 50 cm, so you cut it to whatever shape your canister, sump or internal chamber needs. It is biochemical cotton, meaning bacteria colonise it, so it filters mechanically and biologically at the same time.
Why fish keepers choose it
- ✔ 3 cm thick sheet — substantial enough to hold its shape
- ✔ Cut to fit — no paying for a proprietary-shaped sponge
- ✔ Biochemical cotton — hosts the bacteria that process waste
- ✔ Four sizes — up to 100 x 50 cm for larger chambers
- ✔ White, easy to monitor — you can see when it needs rinsing
At a glance
| Thickness | 3 cm |
| Sizes | 100×13.5cm, 100x30cm, 50x50cm, 100x50cm |
| Colour | White |
| Type | Biochemical cotton foam |
| Cleaning | Squeeze in tank water |
Which size do you need?
Measure the chamber your aquarium filter foam has to fill, then add a little extra so the sheet presses against the sides — water should be forced through the foam rather than around it. For a slim internal filter the 100 x 13.5 cm sheet is usually enough; for a large sump or a multi-stage canister, the 100 x 50 cm size gives you more sheets from one piece. Two layers of 3 cm foam can be stacked where a thicker block is needed.
Care
Squeeze the foam out in tank water during water changes rather than rinsing it under the tap, which would kill the bacteria living in it. A white foam makes it obvious when it is clogged, so check it at each change. Replace the sheet once it loses its spring and compresses permanently.
What’s in the box
1 x sheet of aquarium filter foam, 3 cm thick, in your chosen size.
Servicing a filter? Browse our filtration and water equipment, or add the activated carbon media bags for chemical filtration.
For information on aquarium filtration, see the PetMD fish care guide.
| Weight | 14 lbs |
|---|---|
| Dimensions | 10 in |
| Power (W) | None |
| Type | fish |
| Color | White |
| Size | 100cmx13.5cmx3cm, 100x30x3cm, 50x50x3cm, 100x50x3cm |
| Thickness | 3cm |
| Choice | yes |
Reviews
There are no reviews yet.

Reviews
There are no reviews yet.