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Wildlife pond liner

Updated: 22 October 2026

The sheet in the basket says it is safe for fish. That line is a materials claim on thin film, not a plan for the pond. A wildlife pond liner needs one bank animals can climb, a depth the wildlife guides publish, rainwater, and no fish. The twelve sheets in our [pond membrane comparison](/hub/garden-ponds/pond-membrane) are polyethylene film and LDPE, not the butyl or EPDM the RSPB and the RHS name, and none is a child-safety cover. Thickness sits on the [pond liner buying guide](/hub/garden-ponds/pond-membrane/sub/pond-membrane-buying-guide). Overlap and fleece sit on [how to fit a pond liner](/hub/garden-ponds/pond-membrane/sub/pond-membrane-how-to-fit). Peter F. checked the listings on 20 October 2026. A qualifying purchase can earn us a commission at no extra cost to you.

The sheet in the basket says it is safe for fish. That line is a materials claim on thin film, not a plan for the pond.

Our top picks

PondKraft PondKraft pond liner, 3 x 2.5 m

Best overall

PondKraft PondKraft pond liner, 3 x 2.5 m
8.6/10about £14.99
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GARDENIX GARDENIX pond liner, 1 x 1 m, 200 gsm

Rank 2

GARDENIX GARDENIX pond liner, 1 x 1 m, 200 gsm
6.2/10about £6.72
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WARM&LOVE WARM&LOVE pond liner, 2 x 3 m, 0.1 mm

Rank 3

WARM&LOVE WARM&LOVE pond liner, 2 x 3 m, 0.1 mm
5.5/10about £6.99
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On this page
  1. 1.The shape wildlife can leave
  2. 2.How deep, when you are not keeping fish
  3. 3.Fish, spawn and tap water
  4. 4.Children and the liner

The shape wildlife can leave

A hole with steep sides holds water and traps the animals you hoped to attract. The RHS wildlife pond notes ask for at least one long shallow slope, so a frog or a newt can walk out. If your only water is a half barrel, rest a rough plank or stones from the water onto the rim. Reviews of the small GARDENIX sheet include a wildlife pond only where extra membrane went underneath. Fleece is still not in the box. Plant species belong with aquatic plants. The RSPB names PVC, butyl or EPDM. These rows are not that liner.

How deep, when you are not keeping fish

Two UK sources publish two depth bands, and they should stay two. The RHS puts a wildlife pond at about 20–60 cm. The Freshwater Habitats Trust says that if you are not keeping fish, 25–30 cm at the deepest point can be enough. A middle of 25 cm can meet the Trust and still sit inside the RHS band. Averaging the two would invent a third figure nobody published. Write the depth you chose before you order. Depth does not repair a sheet that UK reviews describe as puncturing on the first night.
PondKraft PondKraft pond liner, 3 x 2.5 m

Testsieger

PondKraft PondKraft pond liner, 3 x 2.5 m
8.6/10about £14.99
View offer

Fish, spawn and tap water

A title that says the plastic is harmless to fish is easy to read as permission to add them. The wildlife guides say the opposite. The RSPB shop PDF says do not add fish or spawn. Froglife says fish eat the other life in the pond. A safe-for-fish bullet is a materials line on the sheet, not a lab result for any of these twelve listings. Rainwater is the fill those guides prefer. The Freshwater Habitats Trust contrasts it with nutrient-rich tap water. A water butt is the practical version. If the butt is empty and you use the hose, you are outside that preference.

Children and the liner

A shallow wildlife pond can still drown a child. RoSPA’s pond-safety advice is supervision, a rigid metal grille, a fence of at least 1.1 m, or filling the pond in. It is not printed on any of these twelve sheets. A slope for frogs does not replace a grille, a fence or a filled-in hollow if children use the garden. A thicker LDPE sheet does not either. This page does not crown a sheet.

Common questions

Can I use a £7 sheet for a wildlife pond?
A price around £7 here is thin polyethylene, often near 0.1 mm, and that is not the butyl or EPDM the RSPB and the RHS describe. The RSPB’s rough £50–£100 is for a 3 m by 3 m liner of the kind they name. UK reviews of the thin sheets include a first-night puncture. A cheap film can line a barrel if you accept that risk. It is a weak match for a stony hole you hope to leave for years.
How deep should a wildlife pond be in the UK?
If you are not keeping fish, the Freshwater Habitats Trust says 25–30 cm at the deepest point can be enough. The RHS publishes about 20–60 cm. A 25 cm middle can meet the Trust and still sit inside the RHS band. A 60 cm pocket is more than the Trust says a fish-free pond needs. Pair the depth with one long shallow slope. Steep sides are the shape animals struggle to leave.
Why do the guides say not to add fish?
Froglife says fish eat the frogs, newts and insects a wildlife pond is meant to hold. The RSPB shop PDF says do not add fish or spawn. A bullet that calls the plastic harmless to fish is a claim about the sheet, not an instruction to stock the water, and not a test of these twelve listings.
Is tap water acceptable?
The Freshwater Habitats Trust prefers rainwater to nutrient-rich tap water, and the RSPB shop PDF points the same way. A water butt is the usual way to follow that in a UK garden. The hose, when the butt is empty, is a fallback those guides do not present as the first choice. Rainwater does not remove the need for a slope or a child-safety cover.
How do frogs get out of a raised barrel?
A half barrel has steep sides, the same problem as a pre-formed shell. The RHS says those shells usually need a ramp. Rest a rough plank or a line of stones from the water to the rim, and check it still reaches after you top up. The ramp does not make the barrel safe for a child, and it does not thicken the liner.
Does a liner make the pond safe for children?
No. RoSPA treats an open pond as a drowning risk even when the water is shallow. The measures it names are supervision, a rigid metal grille, a fence of at least 1.1 m, or filling the pond in. The liner holds the water. It is not the grille, and none of these twelve sheets is sold as that cover. Shallow water of 25 cm is still open water.
Should I move spawn from another pond?
The RSPB shop PDF says do not add spawn. Moving it from another garden pond is the transfer that line is written against. Froglife’s Environment Agency point is consent to move wild fish to inland waters in England and Wales. It does not describe Scotland, and it is not a permission to stock this pond. Leave spawn where it is.

Related pages

HDPE film or rubber liner

Pond membrane

Best pond liner for the hole you are lining in 2026

Pond liner buying guide: thickness before the stars

How to fit a pond liner: level the rim, then fill it

Sources

Public UK sources used for this page in October 2026. Prices, stars and review counts are from the twelve amazon.co.uk listings captured on 19 October 2026. A thickness, a 25-year line and a fish sentence are listing claims, not a laboratory result.

  1. RHS, pond construction and repair (retrieved 19 October 2026)
  2. RHS, wildlife ponds (retrieved 19 October 2026)
  3. RSPB, making a wildlife pond (retrieved 19 October 2026)
  4. RSPB shop, wildlife pond guide PDF (retrieved 19 October 2026)
  5. RoSPA, pond safety (retrieved 19 October 2026)
  6. OATA, how to set up a garden pond (retrieved 19 October 2026)
  7. Froglife, Just Add Water (retrieved 19 October 2026)
  8. Consumer Rights Act 2015 (retrieved 19 October 2026)