Tak-It-EZ Pool & Spa › Guides › Water chemistry
Heat, sun, and swimmers all use chlorine faster in summer. Here is what's going on and how to keep up without overdoing it.
People often tell us their pool was perfect in May and cloudy by mid-July, with nothing changed. Something did change: the weather.
Ultraviolet light breaks down free chlorine. Stabilizer (cyanuric acid) slows that down, which is why outdoor pools need some. Too little and the sun eats your chlorine in an afternoon; too much and chlorine stops working well. We check stabilizer on every water test.
Warm water grows algae and bacteria faster, and the chlorine is used up fighting them. A pool in the high 80s simply needs more chlorine per week than the same pool in spring.
Sunscreen, sweat, leaves, and dust all use up chlorine. A busy weekend of swimming can knock the level down more than a quiet week.
In summer, test chlorine and pH at least twice a week, keep stabilizer in range, and run the pump long enough to turn the water over. Bring a sample to the store once a month for the full panel. If keeping up is a chore, weekly service does it for you and logs every visit.