Pool Acid Wash in Centurion and Pretoria

When an acid wash is the right answer

We recommend an acid wash when the surface has a problem that brushing and water chemistry can no longer fix. The most common in Gauteng are calcium scale from hard municipal water, and staining left behind after a pool has been green for a long time.

• Grey or white calcium scale across the surface, not just at the tile line
• Dark algae staining that survives shock treatment and brushing
• Brown or orange metal stains, often from iron in borehole water or corroded fittings
• Leaf and organic tannin stains in the deep end
• A pool that has stood empty or green for months and needs a fresh start
• Preparing a surface for patch repairs, or before selling a property

When it is not the answer

Acid washing is for plaster, marbelite and similar cement-based finishes. Fibreglass pools must not be acid washed — the acid damages the gel coat. Painted pools and pebble finishes need a different approach too. Tell us what your pool is finished with, or send a photo, and we will confirm.

An old surface that is already thin, rough or flaking may not have enough material left to survive another wash. In that case resurfacing is the real fix, and an acid wash would only make the underlying problem worse. We check the surface before we quote and will tell you if we think a wash is the wrong money to spend.

Finally, if the problem is only a line of scale at the waterline, you do not need the whole pool acid washed. Waterline tile descaling is a much smaller job.

Why winter is acid wash season

An acid wash needs an empty pool, and an empty pool is exposed to two risks: groundwater pressure and hot sun. In summer, after thunderstorms, the ground around a pool is saturated. Remove the weight of the water and the pressure from below can lift or crack a shell. Winter on the Highveld is dry, so that pressure is much lower.

Heat is the other reason. A freshly washed surface left empty in full summer sun can dry too fast and craze. May to August is cooler, the pool is out of use anyway, and you lose nothing by having it empty for a few days. By the time September warms up, the pool is refilled, balanced and ready.

How the job runs

The pool is drained and the floor is cleared of leaves and silt. The acid solution is applied in sections, worked with brushes to lift stains and scale, and then neutralised and rinsed away before it can etch too deep. Stubborn areas get a second pass rather than a stronger mix, because controlling depth is what separates a good wash from a damaging one.

Once the surface is clean and rinsed, the waste is neutralised and the pool is refilled. The new surface affects water chemistry for the first weeks, so the water is tested and balanced as it fills and then watched closely. Pumps and chlorinators are checked before the system is restarted.

Refilling: what to expect

Refilling uses municipal water, and how long it takes depends entirely on your water pressure and the size of the pool. A typical Centurion or Pretoria family pool holds somewhere between 30,000 and 60,000 litres, so refilling can run well into the next day. Keep an eye on water restrictions in your municipality before booking, and check that you are not in a scheduled supply interruption that week.

Fresh municipal water has little chlorine and no stabiliser, so the pool needs a full balance once it is filled. Do not swim until the water has been tested and corrected.

Using the empty pool for other jobs

A drained pool is an opportunity. With the water out, you can see and reach things that are hidden the rest of the year: hairline cracks in the shell, a weir that has pulled away from the wall, a light niche seal that has perished, or return fittings that have been weeping for years. If the pool has been losing water, the days it stands empty are the best time to fix the cause.

We look over the shell, the weir, the light and the fittings during an acid wash and tell you what we see. Any repair is quoted separately and done only with your approval, but doing it while the pool is already empty saves you draining it a second time later. If the surface itself is too far gone for a wash to help, this is also the point at which we will talk to you about resurfacing instead.

Making the result last

The same things that made the surface need washing will make it need washing again: hard water, pH left high, and long stretches without chlorine. Keeping pH in range slows calcium scale considerably, and a weekly service prevents the long green spells that leave stains behind.

Because each wash removes a little of the surface, spacing them out preserves the finish. Most pools, looked after properly, only need one occasionally.

How it works

1. 1

   Assess

   Send photos to 081 577 5051. We confirm the surface type and whether a wash is the right fix.

2. 2

   Drain and clear

   The pool is drained and the floor cleared of debris.

3. 3

   Wash

   Acid applied in sections, brushed, then neutralised and rinsed before it cuts too deep.

4. 4

   Refill and balance

   Refilled from the mains, then tested and balanced; equipment checked before restart.

Frequently asked questions