Calcium hardness increaser chart
How much 77% calcium chloride raises calcium hardness, by pool size and ppm, from 5,000 to 40,000 gallons.
| Gallons | Raise calcium by 10 ppm | Raise calcium by 25 ppm | Raise calcium by 50 ppm | Raise calcium by 100 ppm | Raise calcium by 150 ppm |
|---|---|---|---|---|---|
| 5,000 | 0.6 lb | 1.5 lb | 3.0 lb | 6.0 lb | 9.0 lb |
| 8,000 | 1.0 lb | 2.4 lb | 4.8 lb | 9.6 lb | 14.4 lb |
| 10,000 | 1.2 lb | 3.0 lb | 6.0 lb | 12.0 lb | 18.0 lb |
| 12,000 | 1.4 lb | 3.6 lb | 7.2 lb | 14.4 lb | 21.6 lb |
| 15,000 | 1.8 lb | 4.5 lb | 9.0 lb | 18.0 lb | 27.0 lb |
| 18,000 | 2.2 lb | 5.4 lb | 10.8 lb | 21.6 lb | 32.4 lb |
| 20,000 | 2.4 lb | 6.0 lb | 12.0 lb | 24.0 lb | 36.0 lb |
| 25,000 | 3.0 lb | 7.5 lb | 15.0 lb | 30.0 lb | 45.0 lb |
| 30,000 | 3.6 lb | 9.0 lb | 18.0 lb | 36.0 lb | 54.0 lb |
| 40,000 | 4.8 lb | 12.0 lb | 24.0 lb | 48.0 lb | 72.0 lb |
How to read it
About 1.2 lb of 77% calcium chloride raises hardness 10 ppm in 10,000 gallons. Pre-dissolve per the label, since it gets hot.
These are estimates from commonly used dosing figures. Products vary, so follow the label and SDS, add chemical to water, never mix chemicals, and test again after circulating. Local code may set different ranges.
For an exact number on any pool, use the chlorine and acid and alkalinity calculators, or read Calcium hardness and scale.