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How to choose pond filter foam

Updated: 22 October 2026

Pond filter foam is the open-cell sheet that strains solids and can house bacteria. A 20 PPI sheet, a wool roll and a spare that only fits one model suffix are easy to mix up on amazon.co.uk. This guide puts the choice in order: the format, then one grade you can check, then the model name including any plus, and only then the stars. The twelve rows, with shelf prices in GBP, are on the [pond filter mats comparison](/hub/garden-ponds/pond-filter-mats). Peter F. read those listings on 21 October 2026 and did not run a lab test. A qualifying purchase can earn us a commission at no extra cost to you.

Pond filter foam is the open-cell sheet that strains solids and can house bacteria. A 20 PPI sheet, a wool roll and a spare that only fits one model suffix are easy to mix up on amazon.co.uk.

Our top picks

Unbranded Eight-layer filter pad 60 × 40 × 1.5 cm

Best overall

Unbranded Eight-layer filter pad 60 × 40 × 1.5 cm
8.0/10about £8.99
View offer
Borlech Borlech 20 PPI foam 47 × 47 × 2 cm

Best value

Borlech Borlech 20 PPI foam 47 × 47 × 2 cm
8.0/10about £7.99
View offer
INGVIEE INGVIEE foams for 1400EF and 1400EF+

Rank 3

INGVIEE INGVIEE foams for 1400EF and 1400EF+
7.5/10about £13.99
View offer
On this page
  1. 1.Sheet, roll or shaped spare
  2. 2.One grade you can check
  3. 3.Model suffix and holes
  4. 4.Vacuum packs and what as described means

Sheet, roll or shaped spare

A sheet is what you buy when you can measure the chamber and cut. The Borlech foam is £7.99 for a stated 20 PPI sheet, 47 cm by 47 cm and 2 cm, with 4.5 from 314 reviews. An unbranded black sheet is the same price and grade, with 3.6 from 19 reviews. Two saved texts say the Borlech foam fell into black pieces. A roll is a polish after a coarser stage is already in the box. The 5 m wool is £17.99, with 4.5 from 441 reviews. INGVIEE’s bag for the 1400EF and 1400EF+ is £13.99, a third-party set. If the chamber might want a fibre roll, that split is on pond filter wool or foam.

One grade you can check

PPI means pores per inch. A lower number is the more open pad. eFoam’s bands of about 10, 20, 30 and 40 PPI are seller guidance, and colour is not the grade. A rule of thumb here is about 10 coarse, 20 medium-coarse, 30 medium-fine, and 45–50 fine. A single 20 PPI sheet is a one-chamber compromise. Stacking is on coarse or fine pond filter foam. The size line and the bullets must agree. The polyurethane sheet at £8.09 prints 35 PPI on the size line and also offers 20, 35 or 50 PPI. The £10.99 floss puts 50 microns in a bullet, which is a particle size, not a pore count, and it also says 3 cm and 0.3 cm.
Unbranded Eight-layer filter pad 60 × 40 × 1.5 cm

Testsieger

Unbranded Eight-layer filter pad 60 × 40 × 1.5 cm
8.0/10about £8.99
View offer

Model suffix and holes

A plus on the model name is a different basket. INGVIEE’s £16.99 set is titled for the All Pond Solutions 1000EF+. One saved text says the holes do not line up with a 1000EF. The £13.99 set names the 1400EF and the 1400EF+. Three saved texts do not describe a fit failure. Thirty-two reviews are not evidence that the same bag belongs in a 1000. The SunSun pair at £14.49 lists five CBF plates. A bullet says the pair fits the CBF-200T. If your plate says CBF-350, the bullet has not confirmed that plate. Who each row is for is on best pond filter foam.

Vacuum packs and what as described means

Most of these sheets are vacuum packed. The white fleece says a pack should reach 12–15 mm in 48 to 72 hours. One of its eight reviews says the piece looked about 2 m rather than 5 m. Wait for the expansion the listing describes, then measure on the floor. A pad that stays flat, tears, or sheds bits is a different problem from a pack that needs a soak. Water Garden says replace a foam that tears. Under the Consumer Rights Act 2015 the short-term right to reject lasts 30 days. A high star count is not a water-quality result. Practical Fishkeeping separates mechanical straining from the biological stage. Open-cell foam can give bacteria a surface. It does not replace a test kit when the water is green.

Common questions

What does PPI mean on pond filter foam?
PPI is pores per inch. A lower number is the coarser, more open foam. eFoam’s seller bands run about 10, then 20, then 30, then 40. Colour is not that number unless the brand you are matching has said so. A page that prints 20, 35 and 50 has not given you a single grade.
Do I buy a sheet or a shaped spare?
Buy a sheet when you can measure the chamber and cut, and the filter does not rely on centre holes. Buy a shaped spare when the title names your exact model, including a plus. A 47 cm square will not grow holes to match an All Pond Solutions tray.
Will a 1000EF pad fit a 1000EF+?
Treat them as different filters until you have compared the holes. The £16.99 INGVIEE set is titled for the 1000EF+, and one saved review says the holes miss a 1000EF. The £13.99 bag is titled for the 1400EF and 1400EF+, not for a 1000 of either kind.
Why is the foam thin when it arrives?
It has usually been vacuum packed. The fleece listing says 48 to 72 hours to reach 12–15 mm. Measure after that wait. If the sheet is still far under the stated thickness, or a 5 m roll looks about 2 m, that is a description problem under the Consumer Rights Act 2015.
Is a 50-micron claim the same as a PPI?
Microns describe a particle size. PPI counts pores in an inch of foam. The £10.99 floss uses a 50-micron bullet and also disagrees with itself on thickness, 3 cm against 0.3 cm. There is no review line on that listing. The two numbers are not the same scale.
Does a high star count mean the water will be safe?
Stars record what buyers wrote on amazon.co.uk. They are not a test of ammonia, nitrite or green water. The wool roll is 4.5 from 441, and those texts still include thin wool and shedding. A reviewer’s clearer pond is not a measurement.

Related pages

Pond filter comparison

Pond filter mats

Best pond filter foam for the chamber you can measure

Coarse or fine pond filter foam, and which goes first

Pond filter wool or foam inside this filter chamber

How to clean pond filter foam without a full strip

Sources

Public UK and maker sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the twelve amazon.co.uk listings in the comparison snapshot of 21 October 2026. A reviewer’s clearer-water line is not a measurement of ammonia or nitrite. eFoam’s PPI bands are seller guidance, not a measured life for foam in a UK pond.

  1. Water Garden, how to clean pond filter foams (retrieved 21 October 2026)
  2. All Pond Solutions, blue versus white filter foams (retrieved 21 October 2026)
  3. Hozelock, filter maintenance (retrieved 21 October 2026)
  4. Practical Fishkeeping, buying the right pond filter (retrieved 21 October 2026)
  5. eFoam, aquatic filter foam (retrieved 21 October 2026)
  6. Blagdon, filter maintenance (retrieved 21 October 2026)
  7. GOV.UK, discharges to surface water and groundwater (retrieved 21 October 2026)
  8. Consumer Rights Act 2015, section 22 (retrieved 21 October 2026)