pH adjustment doses are approximate — total alkalinity significantly affects the amount of chemical needed for a given pH change. Always fix alkalinity first.
Muriatic Acid (31.45%) to Lower pH — TA at 80–120 ppm
| Pool Volume | pH 7.8 → 7.4 | pH 8.0 → 7.4 | pH 8.2 → 7.4 |
|---|---|---|---|
| 8,000 gal | 8 fl oz | 16 fl oz | 24 fl oz |
| 10,000 gal | 10 fl oz | 20 fl oz | 30 fl oz |
| 12,000 gal | 12 fl oz | 24 fl oz | 36 fl oz |
| 15,000 gal | 15 fl oz | 30 fl oz | 45 fl oz |
| 20,000 gal | 20 fl oz | 40 fl oz | 60 fl oz |
Sodium Carbonate (Soda Ash) to Raise pH — TA at 80–120 ppm
| Pool Volume | pH 7.0 → 7.4 | pH 7.2 → 7.4 | pH 7.0 → 7.6 |
|---|---|---|---|
| 10,000 gal | 8 oz | 4 oz | 12 oz |
| 15,000 gal | 12 oz | 6 oz | 18 oz |
| 20,000 gal | 16 oz | 8 oz | 24 oz |
Notes
- These are approximate starting doses. Always add incrementally and retest.
- High alkalinity (above 150 ppm) makes pH much harder to lower — may need 2–3x these doses.
- Pre-dissolve soda ash in a bucket of water before adding to prevent white cloudiness.
Sources:
- Taylor Technologies — Pool/Spa Water Chemistry Reference