What Affect Does Rain Have on Pool Water?

It’s hurricane season here in Florida. The heavy rains during this time of year can be hard on your pool! Rainwater in the U.S. is acidic. While it isn’t caustic enough to burn your skin, it can harm your pool. The debris and contamination rainstorms leave in your pool can also create a breeding ground for algae.

How Rain Affects pH

Due to industrial gasses released into the air across the U.S., rainwater throughout the country has an acidic pH. While water with a low or acidic pH isn’t toxic to drink, it can be harmful to your pool and uncomfortable to swim in.

The pH of water is measured on a scale from 0 to 14. Water that has a pH from 8 to 14 is basic or alkaline. Water with a pH from 0 to 7 is acidic. Ideally, your pool water should be between 7.2 and 7.8, which is considered neutral.

Acid water is bad for your pool and your body. Water with a low pH can deteriorate grout, tiling, stone, plaster, and concrete. It can make vinyl surfaces brittle, increasing the risk of tears and cracks in your pool’s liner. It can corrode metal pool accessories—such as ladders and railings—and metal components in your pool pump, filter, or heater. If your skin itches or feels irritated after a swim or your eyes sting, your pool water may be acid. These are two of the Affects that low pH has on swimmers. Swimming in acid water also dries out your skin and hair. It can even make your nasal passages sting.

Light rainfalls won’t usually have a significant impact on your pool water’s pH, but heavy rains will. It’s smart to test your pool water after heavy rainfalls. If the pH is too low, add sodium carbonate (soda ash) or sodium bicarbonate (baking soda) to raise the pH.

How Rain Impacts Algae Growth

Heavy rain brings algae with it. Algae spores live in the air as well as on plant leaves. Rain washes these spores into your pool where they can overwhelm your chlorine. If your pool water is acidic, the chlorine will be even less effective. With Florida’s heat, the algae will be able to reproduce rapidly.
You can protect your pool from algae by adding algicide to the water. Unlike chlorine, algicide works just as hard in water with low pH. It also doesn’t evaporate under hot sunlight like chlorine. Adding the optimal amount of algicide to the water (per the container’s instructions) is the best way to prepare your pool before a heavy rain. Rainwater can easily throw off the balance of your pool water. Making a habit of testing and correcting your pool’s pH level after every heavy rainfall will also help your pool stay healthy. Maintaining the recommended level of algaecide in your pool will keep the water clean and clear. If you need help balancing your pool water, stop by Pool Works! Our pool experts are here to answer your question!