Pool Chemical Dosage Calculator
Test your pool water, enter the readings, and get exact grams of chlorine, soda ash, or baking soda to add — calculated for your pool volume, not a specific product brand. Works in litres or gallons. Nothing uploaded.
Current Status
Treatment Plan
Free Chlorine
pH
Total Alkalinity
Cyanuric Acid
Important Notes
- Never mix pool chemicals together before dissolving in water.
- Add pH/alkalinity chemicals at least 4 hours before or after chlorine shock.
- Re-test after 4–8 hours of circulation before adding more chemicals.
- Doses are based on 100% pure active ingredient. Adjust for your product's stated concentration.
Learn more: pool chemistry and chemical dosing
pH, alkalinity, and chlorine levels - what the numbers mean
Pool chemistry relies on three key measurements: pH (acidity), total alkalinity (buffer capacity), and chlorine (disinfectant). Ideal pH is 7.2-7.6. Alkalinity (typically 80-120 ppm) keeps pH stable. Free chlorine should be 1-3 ppm. Low pH makes water corrosive to equipment; high pH makes chlorine less effective and causes cloudy water. Alkalinity too low causes pH to swing wildly when you add chemicals.
How pool volume determines chemical dosing
All chemical doses are calculated per 1000 gallons (or per 1000 liters). A typical residential pool is 15,000-20,000 gallons. If you add chlorine at 15ppm rate (shock treatment), you multiply 15ppm × (pool volume in thousands of gallons) = pounds of chlorine needed. The calculator does this math instantly for any pool size and target chemical level.
Why you test after waiting and never mix pool chemicals
After adding chemicals, wait at least 30 minutes before testing - chemicals need time to fully dissolve and distribute. Never mix chlorine with other pool chemicals, especially acidic products like muriatic acid - the reaction can be explosive. Always add chemicals to water, never water to chemicals. The calculator shows dosing amounts; safety procedures are equally important.
FAQ
How often do I test pool chemistry?
Minimum twice weekly during swim season. Once weekly in winter. Daily if you have heavy use or warm weather. Test kit accuracy degrades over time - replace strips yearly.
What is the correct order for adding chemicals?
Always add alkalinity increasers first, then pH adjusters, then chlorine. Never add chlorine with any other chemical at the same time - the reaction can be explosive.
Why is my pH always drifting?
Low alkalinity cannot buffer pH. Increase alkalinity to 80-120 ppm first, then adjust pH. With proper alkalinity, pH will be much more stable.