How to Tackle Calcium Buildup on Your Pool Tiles

Maintaining the chemical balance of the water in your pool is one of the more difficult tasks you face as a pool owner, and failure to do so may have serious consequences. One of those is the buildup of calcium deposits on the pool walls, which damages the surface and, if left untreated, can eventually make your pool unswimmable. This article will detail how to remove calcium buildup on pool tiles.

The methods used to remove calcium buildup depend on which compound is involved. Calcium carbonate is by far the most common and can be removed by physical scrubbing or using chemicals. Calcium silicate is much harder to remove, and professional expertise may be needed to eliminate it.

Calcium builds up in your pool through several factors, most importantly the existence of chemicals in the municipal water supply, high evaporation levels in hot weather, and thirdly the pH levels in your pool. This article looks at the various methods available to remove it. Once that has been achieved, I’d also like to show how to ensure that it has been permanently removed so that you don’t have to repeat the whole exercise in the future. Let’s begin the step-by-step process.

How To Remove Calcium Buildup On Pool Tiles

Identifying the calcium deposit will ensure you’re using the right method to remove it.

Identify The Scale – Calcium Carbonate Or Calcium Silicate?

A few drops of muriatic acid placed on a sample will answer the question. Calcium carbonate will foam immediately, whereas calcium silicate won’t react.

Calcium carbonate forms white flaky scales and is pretty easy to remove. Calcium silicate is whitish grey, takes longer to form, and may then also be present in the pipes and filtration system. If so, you may need expert help to solve the problem.

Because calcium carbonate is far more common, I’m going to concentrate on how to remove this compound from your tiles.

Assemble The Necessary Equipment

It’s important to have everything prepared before you start the treatment in order to work quickly and safely. You will need:

  • A pair of protective rubber gloves
  • A pair of goggles to protect your eyes from cleaners and calcium
  • A large spray bottle
  • A hard-bristled brush or scourer, pumice stone, and a scraper
  • Your choice of solvent. For less severe buildups, you could use a 50/50 mixture of white vinegar and water or a commercial (preferably acid-free) calcium remover for stronger action. In the most severe cases, muriatic acid is an effective solvent.

Drain The Pool Enough To Expose The Affected Tiles

Especially if you’re going to be scraping and scrubbing the tiles, it’s essential to have them exposed, as the solvent will have to stay on for some time before being removed. This will mean dropping the level a few centimeters below the normal water line.

Apply The Calcium Cleaner

If you’re using the water/vinegar solution, use the spray bottle to apply it generously to the tiles, then allow it to remain for 20 – 30 minutes to allow it to dissolve the calcium.

  • You can also use a thick paste made from a mixture of vinegar and bicarbonate of soda, which you apply to the affected tiles, and leave it on for the same period of time.

Using a non-acid commercial cleaner or descaler may be more effective for more stubborn buildups. Follow the manufacturer’s instructions on the container and be aware of all safety precautions they advise.

  • Muriatic acid, also known as spirit of salts or hydrochloric acid, can also be applied with a spray bottle, but be very cautious – don’t attempt to spray it in windy conditions, wear protective gloves and goggles, and don’t get into the pool while using it.

Scrub The Tiles To Remove Calcium

Now for the elbow grease! Gently remove the calcium deposit using the non-abrasive scourer, scrubbing brush, and scraper (for the stubborn areas). Too much pressure may result in scratched tiles, so work in a circular motion without being too energetic.

If you find that the scourer and scrubbing brush are not sufficiently effective, try using a pumice stone. Ensure that the stone and the tiles both remain wet and don’t apply too much pressure to avoid damaging the surface of the pool.


Rinse The Solvent From The Tiles

Once the scale has been removed from the tiles, you must clean them thoroughly to remove any remaining solvent and residual calcium. You can do this best by spraying the tiles with clean water under pressure – your garden hose should work fine.

Remove The Calcium From Your Pool

You’ve now got your tiles clean, but the buildup is now in the water and must be removed. Vacuuming by hand is one way, but an automatic pool cleaner will do a better job as it can remain working for as long as necessary.

You can also use a flocculant in the pool, which solidifies the dissolved calcium into a solid material, which is then more easily vacuumed and removed.

An Alternative Method Of Removing Calcium Buildup

Another option, if the methods discussed don’t work, is to call in the professionals with their specialized equipment to remove the calcium buildup in your pool.

They will have the knowledge and the necessary equipment to remove calcium silicate as well as calcium carbonate. They may use “bead blasting,” whereby sand particles or similar beads are applied under pressure to literally blast the calcium off your tiles. It’s quick, very effective, but unfortunately, quite an expensive option.

Preventing Calcium Buildup In Your Pool

You can’t do much about “hard” municipal water with a high calcium content, but you can limit the buildup of scale by

  • Keeping the pH level between 7.4 and 7.6.
  • Reducing evaporation by installing a pool cover.
  • Using a flocculant once or twice a year to coagulate the calcium into solids which can then be removed from the pool.
  • Regularly scrubbing and cleaning the tiles to prevent the buildup of calcium.


While prevention is always better than cure, there are several ways to remove calcium buildup in your pool. Failure to do so will result in permanent damage to the pool. It will also result in swimmers suffering skin irritation, burning eyes, and other ill effects. By explaining the various steps, I’ve hopefully made the task relatively undemanding and easy to carry out – let me know!