You can’t lower what you don’t measure. Invest in a good DPD test kit or digital tester (the ones that use little tablets are wonderfully retro). Test your water twice—once in the morning, once after any adjustment. The ideal free chlorine level for most residential pools is 1 to 3 ppm. Anything above 5 ppm will feel like a chemical bath, and above 10 ppm, you’re entering “swimming in bleach” territory. Numbers don’t lie, but they can definitely ruin a Saturday.
One last fun fact: In the 1950s, pool owners used copper sulfate to kill algae—and it turned swimmers’ hair green. Chlorine may be harsh, but at least it preserves your highlights. Progress.
