Pool Chemicals Explained

Quick reference for common pool chemicals. Use our calculators to get the right dose for your pool size.

Chlorine

Sanitizer that kills bacteria and algae. Keep free chlorine at 1–3 ppm. Available as liquid (10%), granular shock, or tablets. Use our Pool Chlorine Calculator.

pH increaser

Raises pH when it’s too low (below 7.2). Usually soda ash or sodium carbonate. Low pH can damage equipment and irritate skin. Use our Pool pH Calculator.

pH reducer

Lowers pH when it’s too high (above 7.6). Usually dry acid (sodium bisulfate) or muriatic acid. High pH reduces chlorine effectiveness and can cause scaling. Use our Pool pH Calculator.

Shock

High-dose chlorine (granular or liquid) used to quickly raise chlorine, often to 10+ ppm. Use after heavy use, rain, or when water is cloudy. Use our Pool Shock Calculator.

Stabilizer (CYA)

Cyanuric acid protects chlorine from sunlight. Keep 30–50 ppm. Too high and chlorine doesn’t work well; too low and chlorine burns off fast. Use our CYA Calculator.

Last updated: April 2026