How Rain Affects Pool Water

If your pool is not covered and it starts raining, the rain is acidic and can cause the chemistry of your pool to be off. Rain leaves behind minerals, carbonates, and dissolved solids on earth, as it evaporates into the air. As rain falls it picks up small amounts of pollutants, spores, dust, and other contaminants. Depending on how much rain enters the pool, it can overflow your pool and cause even more issues. To learn how rain affects your pool water then keep on reading. 

Chemical Imbalance 

No matter how much it has rained, it will throw off the chemical balance in your pool. Low alkalinity and PH levels in pools can create corrosive water and be bad for pool surfaces, metals, and rubbers used around the pool. Rain will decrease your total alkalinity level and will require an increaser to correct this. Even though rain water does not have a high PH balance, it can still affect your pool water. After it has rained you should check the pool's PH balance and correct it as needed. Rainwater may also create a high chlorine demand, this is because there is more water in the pool and the contaminants will affect it as well. 

Remember the ideal levels in your pool should be: 

• Total Alkalinity: 80–120 ppm
• pH: 7.4–7.6
• Calcium Hardness: 200–400 ppm
• Cyanuric Acid: 30–50 ppm

Water Overflow 

If there is heavy rain there may be an overflow of water in your pool. An overflow of water can compromise your filtration system. This means your skimmer will be blocked and will not get debris from the surface of the pool. Water overflow can also cause damage to the pool walls because of all the pressure. Your pump can also be damaged from an overflow of water leading to short-circuit and other permanent damages. If your pool's equipment becomes damaged, it will need repairing or replacing entirely and this can be costly. After it has rained, you should inspect all the pool equipment to ensure everything is working properly. You should also clean the pool filter before and after recovering your pool from a downpour. 

Algae and Cloudy Water 

Rainwater brings phosphates, nitrates, and other organic contaminants causing algae to grow. Leaf tannins, pollen, and forms of chlorophyll can also enter your pool from the winds and this can also cause algae growth. The sunlight can also accelerate growth for algae especially if you live in a warmer area. To get rid of this algae you will have to add algaecide. Cloudy water also can happen because chlorine levels have dropped. Using a clarifier will help clear up the cloudy water. 

Overall, rainwater may seem harmless but it is acidic and can cause a numerous amount of problems. Rainwater brings a variety of chemicals, minerals, and pollutants into your pool. If it is just a drizzle or light rain, it is best to check the levels of your pool water and adjust as needed. If it was a huge storm then it is best to check all of your equipment and go through a variety of steps to fix your pool. As long as you are checking the water level and adjusting water chemistry as needed after it rains, you should be in good shape. 

If you have any questions or need help looking for a product for your pool please give us a call at 602-854-9058 or send us an email at [email protected]. We have a fantastic team of pool professionals to help direct you to the right sources. Also, check out our YouTube videos where our pool professionals go over how to do installs, quick fixes, and more.