How Fall Weather Impacts Your Pool Water

1. Falling Leaves = Increased Organic Load: Leaves, acorns, pollen, and debris introduce phosphates and tannins into your pool. This causes the pH to rise, water to turn cloudy, and excess algae growth.

2. Cooler Temperatures Slow Chlorine Efficiency: Cold weather slows chlorine’s ability to sanitize water effectively. This often results in higher combined chlorine, more frequent shock requirements, and stubborn algae patches.

3. More Rain = Diluted Chemicals: Northeast storms can quickly dilute stabilizer (CYA), chlorine, and alkalinity. You may see fluctuating pH, low chlorine even after adding it, and corrosion risks from low alkalinity.

4. Shorter Days Reduce UV Exposure: Less sunlight slows algae growth but it also affects chlorine degradation differently than in summer. This means chlorine might last longer, but still needs monitoring.


How to Fix These Fall Water Chemistry Challenges

1. Skim, Brush & Vacuum More Often: Stay ahead of debris to prevent algae and phosphate buildup.

2. Test Your Water Weekly: Focus on pH (7.2–7.6), Alkalinity (80–120 ppm), Calcium hardness (200–400 ppm), CYA/Stabilizer (30–50 ppm), and Chlorine (2–4 ppm).

3. Shock the Pool After Heavy Rain or Leaf Storms: This resets chlorine efficiency and helps oxidize organic waste.

4. Balance Chemicals Before Closing: If you’re closing your pool for winter, fall is the most important time to balance water correctly to protect plaster, tile, and equipment.

5. Schedule a Professional Fall Cleaning: A deep clean before closing or winter maintenance prevents spring surprises.