Installing Your Pool, Stage 8: Fitting The Skimmer And Completing The Fill

Where you are: structure complete, top seats and caps on, safety labels fitted, water sitting at the base of the wall from the liner stage. If you are not there yet, go back to stage seven.

What you will have finished with: skimmer installed and a full pool.

This is the easiest stage in the series and the longest in elapsed time. Most of it is a garden hose doing its job while you do something else.

There are two things worth your attention though, and one of them is the last irreversible step in the whole installation.

First: fit the skimmer

Your skimmer is the opening in the wall that draws surface water toward the pump. It has to be installed before the water gets up to it, so it goes in now.

Follow the instructions that came with your skimmer, since the fitting details vary. But there is one principle that carries over from the return fitting you installed in stage six, and it is the important one:

Position and secure the ring first. Cut the liner last.

That is the sequence your assembly instructions specify for the return fitting, and it applies just as much here:

Place the skimmer faceplate or ring against the liner
Adjust until it is perfectly aligned with the opening in the wall
Secure it in position
Only then cut the liner inside the ring
Fit the gaskets, with one between the fitting and the liner and one between the wall and the liner
Tighten evenly, taking care not to crease the liner

Do not rush this because you are close to finished. Two liner cutouts, two chances to get it wrong, and this is the second one. A misaligned skimmer cut is not something you can move.

Even tightening matters. A creased or unevenly compressed gasket at the skimmer is the single most common slow leak on an above ground pool, and it is the leak that causes wall rust years later. Firm and even all the way round.

Take your time. You are twenty minutes from being done.

Then: fill it

Turn the hose on and leave it.

Expect this to take a while. Depending on your pool size and your water pressure, filling from a garden hose takes anywhere from several hours to more than a day. A larger pool on ordinary household pressure is often an overnight job.

If you are having water delivered by truck instead, this part is much faster. Our cost guide covers the trade-off between the two.

Do not leave a running hose completely unattended overnight if you can avoid it. Check on it periodically. An unattended overfill is a waste of water and a soggy yard, and a problem that develops while nobody is watching gets worse than one you catch early.

Where to stop

Fill to about the middle of the skimmer opening.

That is the level the skimmer is designed to work at. The weir door needs water flowing over it to skim the surface properly.

Too low and the skimmer starts pulling air along with water, which means poor circulation, a pump that struggles to stay primed, and a filtration system that does not do its job.

Too high and the skimmer cannot skim, because there is no surface flow over the weir. Debris just sits on the water instead of being drawn in.

Mid-skimmer is the target, and it is the level you will be topping back up to all season as water evaporates.

Two things to watch while it fills

1. Wrinkles, while you still can

If you have wrinkles in the liner floor, the window to fix them is closing.

While the water is shallow, in clean flat-soled shoes or bare feet, you can still push a wrinkle outward from the centre toward the walls. Once the water is more than about knee deep, the weight has pinned the liner and that option is gone.

Small wrinkles are cosmetic and plenty of pools have a few. Deep folds are worth dealing with now, because they collect grit and are a common origin point for leaks years down the line. Our post on wall buckling and liner wrinkles covers the fixes.

2. The wall

Walk around the pool every so often as the level comes up.

If the wall starts to deform, bulge or flex anywhere, turn the water off immediately and assess before adding more. A wall that is telling you something at half fill will not sort itself out with more weight on it.

Also check your two fittings as the water rises past them. A weep at the return or the skimmer is much easier to address now than after the pool is full.

The moment of truth on your base

Here is the thing nobody warns you about, and it is worth knowing before it happens.

Water finds level instantly and perfectly. It does not care how carefully you measured. As the pool fills, the water line becomes a dead level reference running around your pool, and if your base is off, you will see it as a difference in how far the water sits below the top rail from one side to the other.

This is the moment stage two gets graded.

If it is out by a small amount, that is normal and most pools have some variation. If it is out by a noticeable amount, that is worth a conversation before you finish filling, because draining a partly filled pool is far easier than draining a full one.

Our base preparation guide covers what "acceptable" looks like.

Do not swim yet

The pool is full and it looks finished. It is not.

Your filtration system is not running yet, which is stage nine.

Your water is untreated, which is stage ten. Fresh fill water has no sanitiser in it, and untreated water in a warm pool goes bad quickly.

Your barrier and ladder need to be in place, if they are not already.

It is very tempting at this point. Give it another day.

Before you move on

Skimmer ring positioned and secured before any cutting
Liner cut only after the ring was aligned and fixed
Gaskets fitted correctly on both sides of the liner
Skimmer tightened firmly and evenly with no creasing
Pool filled to the middle of the skimmer opening
Wrinkles worked out while the water was still shallow
Wall checked periodically during filling, no deformation
Return and skimmer checked for weeps as the water passed them
Water line checked against the top rail all the way round
Nobody swimming until filtration and chemistry are sorted

The short version

Fit the skimmer before the water reaches it.
Position and secure the ring first, cut the liner last. Same rule as the return fitting, and this is your second and final cut.
Tighten the skimmer evenly. An uneven gasket here is the most common slow leak on an above ground pool.
Fill to the middle of the skimmer opening. Too low pulls air, too high will not skim.
Filling takes hours to more than a day on a garden hose. Check on it.
Work out any remaining wrinkles while the water is still shallow.
Walk around the pool as it fills. If the wall deforms, turn the water off.
The rising water line is a perfect level. This is when you find out how good your base is.
Do not swim yet. Filtration and chemistry come first.

Next in this series: the filtration system. Setting up the pump and filter, connecting the hoses in the right order, and getting it running.