Quick Reference Guide
Raising Levels
| Chemical | To Raise | Add |
|---|---|---|
| Free Chlorine | +1 ppm | Liquid chlorine, cal-hypo, or dichlor |
| pH | +0.1 | Soda ash (sodium carbonate) |
| Alkalinity | +10 ppm | Baking soda (sodium bicarbonate) |
| Calcium Hardness | +10 ppm | Calcium chloride |
| Cyanuric Acid | +10 ppm | Stabilizer/conditioner |
Lowering Levels
| Chemical | To Lower | Method |
|---|---|---|
| Free Chlorine | -1 ppm | Wait it out, or use sodium thiosulfate |
| pH | -0.1 | Muriatic acid or dry acid |
| Alkalinity | -10 ppm | Muriatic acid (add slowly) |
| Calcium Hardness | Any | Partial drain and refill |
| Cyanuric Acid | Any | Partial drain and refill |
Common Target Ranges
Use these as general residential pool targets, then follow any limits set by your surface, sanitizer, or equipment manufacturer:
- Free Chlorine: 2-4 ppm (with CYA) or 1-3 ppm (without)
- pH: 7.4-7.6
- Total Alkalinity: 80-120 ppm
- Calcium Hardness: 200-400 ppm
- Cyanuric Acid: 30-50 ppm
Dosing Checklist
- Test before adding chemicals - Always know your starting point
- Add chemicals with pump running - Helps distribute evenly
- Wait between additions - Give at least 30 minutes before retesting
- Never mix chemicals - Add one at a time to the pool
- Add acid to water - Never water to acid when diluting
How to Use This Pool Chemical Calculator
Test the water before opening a chemical container. The calculator uses that current reading, your target, pool volume, and product strength to estimate a dose. For example, if free chlorine is 1 ppm and your target is 3 ppm, enter both values instead of estimating from the jug.
Correct one parameter at a time and keep the pump running while the product disperses. Total alkalinity can affect how pH responds, so stabilize large alkalinity errors before repeatedly adjusting pH. Follow the product label for circulation and retest times; 30 minutes is not sufficient for every chemical or test.
Confirm the pool volume before dosing. A 10% error in the gallon estimate creates roughly the same error in a volume-based dose. If the volume is uncertain, calculate it first and add only part of the estimated dose before retesting.