5 Things to Know About Calcium Scale on Pool Tiles

White scale on pool tiles is calcium carbonate from hard water. It forms when pool water has high calcium hardness and pH drifts up, leaving calcium behind as water evaporates.

Vinegar will make it worse. Vinegar is acidic and will etch tile grout and damage stone or plaster surfaces.

Use a pumice stone for glazed ceramic tiles. Scrub lightly with a wet pumice stone. For glass tiles or milder deposits, use a non-acidic tile cleaner with a stiff nylon brush.

For baked-on scale, use a professional-grade sulfamic acid cleaner. Follow the instructions exactly — too strong and you will damage the grout.

Prevent new scale by keeping pool chemistry balanced. Maintain calcium hardness at 200-400 ppm and pH at 7.4-7.6.