How Heavy Rains Affect Pool Chemistry

Publication date : Thursday, June 13th, 2019

It’s summer in Mississippi! We’ve seen lots of heavy rain this year, and many pool owners ask how the rainfall affects their pool chemistry. Because rainwater has acidic properties, it can mess with your pH balance and alkalinity levels. Fortunately, you don’t have to let all your hard work go to waste. By keeping ahead of your water chemistry and testing more frequently during rainy periods, you can keep your pool water clean, healthy and pristine. 

Why is Rainwater a Problem? 

You might think that rain is natural, distilled water, but that’s not the case. Rain is formed from evaporated water and contains minerals that are dissolved into the soil and evaporated into the air. It’s a simple, organic process. The problem is that as the rain falls through the air, it comes into contact with contaminants, such as pollutants, spores and dust. This is what changes rainwater and makes it more acidic

Additionally, too much rain can cause your swimming pool to have a dangerously high water level. Your skimmer might stop working, and high winds might bring branches, leaves and other debris into your pool. Other problems you might see from high rains are: 

  • Cloudy water 
  • Reduced chlorine levels 
  • Decreased total alkalinity 
  • Decreased pool hardness (only a problem if your water is soft) 
  • Lowered pH levels 
  • More algae 

How to Care for Your Pool During Heavy Rains

You can’t stop a rainstorm, but you can protect your pool. We’ll teach you how. 

What to do BEFORE it rains 

If you know that it’s going to be a particularly rainy week in Mississippi, there are things you can do before the storms roll through. Rainfall dilutes levels, so start by boosting chlorine levels to handle the extra demand. Drain excess water to prevent pool equipment from flooding. Don’t drain water below the skimmer, as you could run the pump dry. Also, trim back trees to keep debris out of your pool. 

What to do AFTER it rains 

Test your water more frequently during periods of heavy rain. This way, you will know what your pool water needs. Depending on the results, you may need to add a pH increaser, alkalinity increaser, calcium hardness increaser and/or clarifiers and enzymes. If your water is cloudy and green, you may have to shock it. 

Pools need extra TLC during rainy weather. If you need assistance managing your pool, give Paradise Pools a call or stop in and visit us. We’ll be happy to explain what types of chemicals are needed to keep your pool in pristine condition. 


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