Cal Hypo Explained: The Good, The Bad & The Calcium

What if your “quick shock” could bleach a liner, stain a step, or even trigger an explosive reaction in your feeder? We take a hard, practical look at calcium hypochlorite—cal hypo—and share how pros use it for powerful oxidation without piling on cyanuric acid. From real-world dosing to regional water chemistry, we map the choices that keep your pool clean and your surfaces safe. We start with clarity on strength: why 73 to 78 percent cal hypo nearly matches a gallon of 12.5 percent liquid ...