Taking care of a pool during a heatwave or in a generally hotter climate requires particular attention to ensure the water remains clean, safe, and comfortable for swimmers. As the sun blazes and water temperatures increase, factors such as rapid chlorine dissipation, increased bacterial growth, water evaporation and more come into play. If proper precautions and checks aren’t taken, it’s very easy for algae and bacteria to take over. It may seem intimidating, but don’t worry! The Pool Pros at Doheny’s have come up with a guide to help you understand the effects of hot weather and how to handle it.

Effects of High Temperatures on Water Chemistry

Chlorine & Heat: Chlorine tends to be most effective between 70 - 80 degrees Fahrenheit. Once water has surpassed the 80 degree mark, several factors can start to affect chlorine’s ability to sanitize the pool.

  • Accelerated Dissipation - In general, higher temperatures accelerate chemical reactions, including the breakdown of chlorine molecules. This leads to faster chlorine depletion in pool water above 80 degrees. Direct sunlight, such as ultraviolet rays, also play a part in chlorine breakdown.
  • Reduced Effectiveness - Higher temperatures render chlorine less effective as a sanitizer. When water gets too warm, chlorine’s ability to kill bacteria, viruses, and algae decreases.
  • Formation of Chloramines - Chloramines result from chlorine combining with organic matter in your pool. The warmer the water, the more accelerated the formation of chloramines, which give off a strong odor and can cause skin and eye irritation.  
  • Increased Demand for Chlorine - Higher temperatures lead to increased microbial and bacterial activity and growth. This means chlorine is used up at a more rapid rate to counteract the new organic matter, requiring more to be used overall to maintain clean water.

Other Water Chemistry Concerns:

  • pH Imbalances - Hot temperatures can make pool water become more alkaline, unbalancing your pool’s overall water chemistry.
  • Water Level - Higher temperatures lead to increased water evaporation, potentially putting your water level outside of the optimal range.
  • Algae Growth - Warmer water is more apt to breed algae. As the temperature rises, so does the opportunity for algae blooms.

Recommended Pool Care Steps

  1. Run your filter constantly. This keeps your water moving, promoting clear water and making it harder for algae to form. Remember, the more stressed the water, the more attention and water agitation it needs!
  2. Test your water at least three times a week and balance accordingly. This helps to ensure your chlorine, pH, and general chemical levels are where they need to be due to the decreased chemical efficiency and increased chemical consumption. Make sure to have extra balancing chemicals in tow, as well as some algaecide in case of an unexpected breakout.
  3. Cover your pool when not in use or at night. Any shade can mitigate excess water evaporation due to the sun, and keeping your pool covered overnight helps prevent heat loss. Solar covers are the most effective option, but even a few umbrellas covering parts of the pool can help.
  4. Skim, brush, and vacuum your pool more frequently. This will not only allow for you to keep bugs, leaves, and debris from piling up in your water, but also help prevent algae from sticking to pool surfaces.
  5. Shock your pool regularly to both help eliminate algae and break down chloramines to restore chlorine effectiveness. For the best results, we recommend our Doheny’s Non-Chlorine Oxi-Shock.
  6. Educate your swimmers on showering before entering the pool. Exterior contaminants, such as body oils and sunscreens, can be introduced and promote bacterial growth if proper pool hygiene isn’t practiced.
  7. Manage your landscaping to minimize the opportunity for debris to land in the pool. Keep any nearby bushes and trees trimmed to help prevent plant matter from falling into the water.

In conclusion, taking care of a pool in a hot climate requires proactive measures and a thorough understanding of the unique challenges posed by increased water temperatures. As long as you stay consistent with your pool care, it should be relatively simple to keep maintained.

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