Cal hypo dose chart
How much 65% calcium hypochlorite to raise free chlorine, by pool size and ppm, from 5,000 to 40,000 gallons.
| Gallons | Raise free chlorine by 1 ppm | Raise free chlorine by 2 ppm | Raise free chlorine by 3 ppm | Raise free chlorine by 5 ppm | Raise free chlorine by 10 ppm |
|---|---|---|---|---|---|
| 5,000 | 1.0 oz | 2.0 oz | 3.0 oz | 5.0 oz | 10.0 oz |
| 8,000 | 1.6 oz | 3.2 oz | 4.8 oz | 8.0 oz | 1.0 lb |
| 10,000 | 2.0 oz | 4.0 oz | 6.0 oz | 10.0 oz | 1.2 lb |
| 12,000 | 2.4 oz | 4.8 oz | 7.2 oz | 12.0 oz | 1.5 lb |
| 15,000 | 3.0 oz | 6.0 oz | 9.0 oz | 15.0 oz | 1.9 lb |
| 18,000 | 3.6 oz | 7.2 oz | 10.8 oz | 1.1 lb | 2.2 lb |
| 20,000 | 4.0 oz | 8.0 oz | 12.0 oz | 1.2 lb | 2.5 lb |
| 25,000 | 5.0 oz | 10.0 oz | 15.0 oz | 1.6 lb | 3.1 lb |
| 30,000 | 6.0 oz | 12.0 oz | 1.1 lb | 1.9 lb | 3.8 lb |
| 40,000 | 8.0 oz | 1.0 lb | 1.5 lb | 2.5 lb | 5.0 lb |
How to read it
One ppm in 10,000 gallons takes about 2 oz by weight of 65% cal hypo, and 1 lb raises it about 7.8 ppm. Cal hypo also adds calcium, so watch hardness on plaster pools.
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 Chlorine types compared.