calcs.homes
calcs.homes
Enter your pool volume and pick how bad the problem is — regular maintenance, a green pool, or heavy algae — to get the shock dose.
Estimate only — shock at dusk or night, and don't swim until chlorine drops back under 5 ppm.
Standard cal-hypo shock (65-73% available chlorine) is typically dosed at about 1 lb per 10,000 gallons for routine maintenance shocking. A green or algae-affected pool usually needs double that, and stubborn black algae can call for triple — always follow your specific product's label, since concentration varies by brand.
Weekly during swim season is typical for routine maintenance, plus after heavy bather load, a storm, or any time the water looks cloudy or green.
Wait until free chlorine drops back to 1-5 ppm, usually 8-24 hours depending on dose and sunlight — test before getting back in.