39. How Rain Affects Swimming Pool Water Chemistry
Rain does more than make the yard look refreshed. In most pools, a storm is basically a chemistry event. Water level rises, contaminants get stirred up, and your sanitizer and pH trends can swing in ways that feel random if you are only watching the pool “normally.” I learned this the hard way after a night of heavy rain. The next morning the water looked fine from across the patio. By midday, the smell changed, the water had a faint haze, and a quick test showed chlorin