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Wide mouth vs standard skimmer

Updated: 16.10.2026

You are choosing a mouth for a rigid above-ground pool, or you hope a wide faceplate will cover the square hole already in the wall. This wide mouth vs standard skimmer page is about those two openings. They are different cuts, different screw patterns, and usually a liner decision. The [wide mouth skimmers comparison](/hub/pool-care/wide-mouth-skimmer) only covers wide-mouth listings. If the inside opening is already wide, buy a wide-mouth body and measure the screws. If it is still standard, keep a standard mouth unless the liner is coming out anyway. The Products Compared editorial team wrote this on 16 October 2026. A purchase through our links can earn a commission at no extra cost to you.

You are choosing a mouth for a rigid above-ground pool, or you hope a wide faceplate will cover the square hole already in the wall. This wide mouth vs standard skimmer page is about those two openings.

Our top picks

Hayward Hayward SP1091WM Dyna-Skim

Best overall

Hayward Hayward SP1091WM Dyna-Skim
9.4/10about £116.11
View offer
FixIdea FixIdea wide-mouth thru-wall kit

Alternative

FixIdea FixIdea wide-mouth thru-wall kit
9.0/10about £89.33
View offer
Hydrotools Hydrotools 8939 wide-mouth skimmer

Best value

Hydrotools Hydrotools 8939 wide-mouth skimmer
8.8/10about £67.52
View offer
On this page
  1. 1.The two openings
  2. 2.Why they do not swap
  3. 3.When the wide mouth is the one to buy
  4. 4.What a wide mouth still will not do

The two openings

A standard above-ground mouth is close to square. Royal Swimming Pools puts it near 5 7/8 by 5 3/8 inches. The same page puts a wide mouth near 5 1/8 inches high by about 11 1/2 inches wide. Doheny prints 5 3/8 by 11 3/4 inches on an 18-hole plate, against about 10 holes on a standard plate, and says the two are not interchangeable. Those fractions are retailer statements, not a British Standard. The wide listings we kept do not settle it. FixIdea states an inner opening of 11 15/16 by 5 5/16 inches. TonGass states a 14 by 7 3/4 inch cutout. Measure the inside face, not the outside housing: width, height, and screw count. The tape method is on the wide mouth skimmer buying guide.

Why they do not swap

A wide faceplate over a square hole leaves metal and liner showing, and the screws miss the old pattern. Inyo’s chooser says that on a replacement you match the original. A larger mouth means cutting the wall. A smaller skimmer than the hole cannot be secured, because the plate has nothing solid to clamp all the way round. Putting the old standard body back into a wide hole fails for the same reason. The liner is the expensive half. A wider cut in a liner that is still good usually means a new liner. In The Swim’s guide, the skimmer comes off with the old liner and goes back once the new one is stretched. That is when a wider mouth costs a cut you were making anyway. Hand tight, in a cross pattern, is the how to install a wide mouth skimmer page if you go ahead. A square winter cover will not seal a wide opening.
Hayward Hayward SP1091WM Dyna-Skim

Testsieger

Hayward Hayward SP1091WM Dyna-Skim
9.4/10about £116.11
View offer

When the wide mouth is the one to buy

Buy the wide mouth when the inside opening is already that rectangle. Trees, an existing wide cutout, and a pump you are tired of helping with a pole net are the practical case. The opening can take larger leaves. No source here measures how many more. Dolphin Pools, a UK shop, describes a wide angle as more surface capture and does not name a cutout. Keep the standard mouth when the debris is light and the hole is still square. Inyo notes that many new above-ground walls are punched for a widemouth such as a Hayward SP1091WM. If you are replacing a skimmer on a pool you own, match the hole you can see today.

What a wide mouth still will not do

The mouth sits at the waterline. Swimline’s manual wants the water about midway up the faceplate, or the pump can lose prime. A wide opening does not vacuum the hopper, and a blocked basket stops the flow whether the mouth is wide or square. The part is unpowered plastic. HSE’s HSG179 does not govern a private domestic pool used only by the owner, family, and guests. A drip under the faceplate can still rust a steel wall. The Emaux EM0140, at £149.99, is an in-ground wide mouth, not a way to enlarge an above-ground standard hole. If your tape says square, buy a standard mouth and leave the wall alone until the liner is due.

Common questions

Can I screw a wide faceplate over a square hole?
The screw patterns differ, so the wide plate will not seal that cut. Widening it means cutting the wall and, if you want to keep the liner, usually a new liner. If the liner is already off, that is the moment. A sound liner and light debris are a reason to keep the standard mouth.
Can the old standard skimmer go back into a wide hole?
A smaller plate cannot clamp a larger opening all the way round. Inyo says the skimmer has to match the hole. You need a wide body, a gasket for that mouth, and screws that meet the wide pattern. The old standard gasket will not bridge the rectangle.
Do I have to replace the liner to go wider?
On a liner still in service, a wider mouth cuts vinyl you cannot slide back, so most people replace the liner. When the liner is already coming off, new gaskets and a wider mouth can go on as it is stretched. A sound liner on a square hole is a reason to wait.
If there are no trees, is the standard mouth enough?
For light debris and a square hole, yes. Wide is the match when the wall is already cut wide, or when the liner is off and you choose to enlarge the panel. An open garden does not force a new hole. The opening you have comes first.
Does a wide mouth skim the floor?
It skims the surface. The floor still needs a vacuum, and a full basket stops the flow on either mouth. Swimline wants the water about midway up the faceplate, or the pump can lose prime. Extra width takes larger leaves at the waterline only.

Related pages

Best wide mouth skimmer

Wide mouth skimmer

Wide mouth skimmer buying guide: measure the cutout

How to install a wide mouth skimmer on a rigid wall

Above ground skimmer leaking at the faceplate joint

Sources

Manufacturer pages, GOV.UK, and HSE, plus the sizing note marked as a US shop. Prices and ratings are amazon.co.uk listing lines. Retrieved 16 October 2026.

  1. Hayward Dyna-Skim manual IS1091LX (retrieved 16 October 2026)
  2. Hayward SP1091WM Dyna-Skim wide mouth skimmer (retrieved 16 October 2026)
  3. Swimline 8939 wide mouth skimmer installation manual (retrieved 16 October 2026)
  4. Plastica above-ground pool widemouth skimmer, The Pool Cleaners (retrieved 16 October 2026)
  5. HSE HSG179 — Managing health and safety in swimming pools (retrieved 16 October 2026)
  6. Consumer Rights Act 2015, GOV.UK (retrieved 16 October 2026)
  7. Pool Factory — leak on a through-wall skimmer (retrieved 16 October 2026)
  8. Royal Swimming Pools — above-ground skimmer sizing (US shop; not a UK price) (retrieved 16 October 2026)
  9. amazon.co.uk listings for the seven ASINs in this comparison (retrieved 16 October 2026)