Pool tile guide How to remove calcium from pool tile.

First, figure out what you're dealing with

Calcium buildup on pool tile comes in two main forms. Calcium carbonate is white, chalky and often flaky. It forms when the water's chemistry is off and when water evaporates and leaves minerals behind. Calcium silicate is grayer, harder and bonded more tightly to the tile. It usually means the buildup has been there a long time.

A simple test: if a soft nylon brush and a little effort take some of it off, you're mostly dealing with fresh carbonate. If the brush slides over it and nothing happens, it's set-in scale.

What you can do yourself

For a light, fresh line, brush the waterline weekly with a soft nylon brush and keep your water balanced so new scale doesn't form. Keeping the water level steady also helps, because a level that rises and falls dries minerals onto a wider band of tile.

Avoid wire brushes, pumice stones and acid tile cleaners. They can scratch glass tile, etch glaze and wear down grout, and they rarely get scale off evenly. A scratched tile also gives new calcium more to grip.

When it's time for a professional cleaning

Once scale is thick, rough or gray, the practical fix is media blasting. A trained technician sprays a fine media at low pressure that knocks the scale off without grinding the tile. On our jobs, glass tile gets a mineral-based, pH-neutral media, and porcelain, ceramic and natural stone get silica bead. You can read how it works on our pool tile cleaning and calcium removal page.

The pool doesn't have to be drained. The water is lowered about 6 to 12 inches below the tile line, the tile is cleaned, the media is vacuumed out, and you refill. Most pools are done in 2 to 4 hours.

Keeping it off afterward

Balanced chemistry, a steady water level and weekly brushing are what keep calcium from coming back. Raised walls, spillways and waterfalls build up faster from splashing, so brush them weekly too. See how often to clean pool tile for a realistic schedule.