Pool Chlorine Guide
Free chlorine keeps water safe. Use this hub to jump to dosage tables, shock guides, and problem fixes.
What chlorine does
Chlorine kills bacteria and algae and oxidizes contaminants. You measure free chlorine (what is available to sanitize) and sometimes combined chlorine (chloramines), which you want to keep low.
Ideal levels (1–3 ppm)
For most residential pools, maintain 1–3 ppm free chlorine. Test two to three times per week; increase after heavy use, rain, or visible algae.
Common problems
Green water, high chlorine after overdosing, and cloudy water tie back to sanitizer, filtration, and balance. Follow the problem guides below and confirm volume before dosing.
Dosage calculations
Use the primary calculator for exact ounces from your test readings, then cross-check size-based tables on our programmatic pages.
All chlorine & shock pages
- Pool Chlorine Calculator
- Pool Shock Calculator
- How Often To Shock Pool
- When To Add Chlorine
- Chlorine for 10,000 gal pool
- Chlorine for 12,000 gal pool
- Chlorine for 15,000 gal pool
- Chlorine for 18,000 gal pool
- Chlorine for 20,000 gal pool
- Chlorine for 25,000 gal pool
- Chlorine for 30,000 gal pool
- Chlorine for 5,000 gal pool
- Chlorine for 7,000 gal pool
- Chlorine for 8,000 gal pool
- Chlorine for 9,000 gal pool
- Chlorine for 10,000 gal pool
- Chlorine for 15,000 gal pool
- Chlorine for 20,000 gal pool
- Chlorine for 5,000 gal pool
- Green Pool How Much Chlorine
- High Chlorine How To Lower
- Shock for 10,000 gal pool
- Shock for 15,000 gal pool
- Shock for 20,000 gal pool
- Shock for 25,000 gal pool
- Shock for 30,000 gal pool
- Shock for 5,000 gal pool
- Typical range: 1–3 ppm chlorine
- Recommended pH: 7.2–7.6
- Test water regularly
WaterBalanceTools provides practical calculators and guides for pool and hot tub water chemistry. These tools are designed to help maintain safe chlorine, pH, and total alkalinity within a healthy water balance.