5 Reasons Your Pool Has High Chlorine Demand

Algae blooms are eating your chlorine Algae consumes chlorine faster than you can add it. Shock the pool to 10–20 ppm free chlorine and brush all surfaces.

Heavy bather load introduces contaminants Sweat, urine, sunscreen, and other organic matter from swimmers use up chlorine. Run the filter 24 hours after shocking.

Organic debris is sitting in the water Leaves, grass, and dirt create a constant chlorine demand. Remove visible debris before adding more chlorine.

Stabilizer (cyanuric acid) is too high CYA above 50–60 ppm blocks chlorine from working effectively. You may need to dilute the pool water.

Hidden algae in crevices or plumbing If chlorine disappears in hours after shocking, check for algae in cracks, behind lights, or in a dirty filter. Stop adding small doses—you need enough to break through the demand.