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  • Writer's pictureA POOL AND SPA

What Effect Does Rain Have on Pool Water?

Owning a pool is amazing! The summertime is filled with days of fun in the sun. There is nothing better than sitting by the pool, swimming laps, or playing sports in the water. That being said, rain will ruin a fun day in the pool. Rain can affect your pool water and change the overall chemistry. The rain can make the pool water unsanitary and visually unappealing. Weirdly enough, the chemical imbalance does not come from the chemicals being diluted in the extra water.

The problem lies in what comes with the water, not how much rain water there is. Algae and other airborne debris is carried with the rain drops and are deposited into the pool. These are what cause the issues with your pool. Algae spores are always floating in the air and can be carried in the wind. They seek out damp places with standing water, and your pool would be a prime target. During the rain these spores get rinsed into your pool water. Spores that are attached to any plants or vegetation also get rinsed off and tend to make their way to your pool.

When this toxic mix of algae and other contaminants get into your pool water, you must take care of it quickly. It can all cause chemical reactions with the chlorine in your water to make it less effective. Also, as organic matter in your pool decomposes, the algae and other organic matter will feed on it and reproduce even faster. If your pool is in a sunny spot and it is hot out, then you are in for a lot of reproduction.

What needs to happen to fix this is that you must kill algae in your pool faster than the rate that it is reproducing. If you are killing algae, but it can reproduce faster than you kill it, then you are not helping things at all. That means purchasing algicide and keeping its level at a high range. This range is recommended on the product’s packaging. Algicide does not decompose in chlorine or sunlight, so it will keep killing algae as long as there is enough in the water to do the job.

Debris in the pool water that gets deposited during the rain can also harm the delicate chemical balance in the pool. After every rainfall, test your pool water to make sure that your chemicals are in balance. If not, then add the right chemicals to get it in balance again. It is also good to test regularly in between rainfalls as well. If you keep your Total Alkalinity in the right range, then it can protect the pool water from the pH of the rainwater causing too many issues. Rainfall is inevitable at some point, so there is no harm in protecting your water.

As you can see, rainwater is not a good addition to your pool. It can provide a breeding ground for some nasty materials that can make you and your family sick. Test your pool regularly to keep your water well-balance to protect and fight against these contaminants before and after rainwater gets into your pool.


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