How Rainwater Can Affect Your Swimming Pool

We all loved chemistry class, right? Whether you were an A+ chemistry student or you just coasted along, if you plan on getting a swimming pool, you’re going to want to brush up on your chemistry, especially water chemistry. 

Changing the chemistry of pool water requires careful consideration and thorough observation of fluctuations. You’d be surprised how much can change by adding too much or too little of one chemical. An excessive amount of any liquid is sure to throw off the water chemistry of your pool. Rain is perhaps the peskiest example.

Ideally, we would be able to track and observe everything that got into pools, but we can’t. That is why it is so important to check your water and test the water chemistry as often as possible. There are a few ways that excessive rainwater can damage your pool, but there are also ways to remedy this and get ahead of any rainwater effects. With that being said, how can rainwater affect your swimming pool? Let’s get into it!

 

Rainwater Effect #1 – Changes Pool Water Chemistry

Rainwater typically has a pH between 5 and 5.5, meaning it is acidic. As you can imagine, that is not the water you want in your pool. The proper range for pH in pool water is anywhere between 7.2 and 7.8.

If your pool is uncovered and you get a heavy rain load, there’s a legitimate chance the rainwater knocked the pH in the water too low. You will want to remedy this as quickly as possible, as acidic water could cause the pool to cloud up.

Always be sure to monitor your pool water chemistry during rain storms. Rainwater is also very soft and could potentially dilute your calcium hardness levels if the pool takes on a lot of rainwater. In addition, rainwater can dilute salt levels in a saltwater pool. If your pool is covered, this is not something you have to worry about. A small amount of rain won’t affect the water chemistry too much, but it is not a bad idea to test the chemistry afterward just to be safe. 

 

Rainwater Effect #2 – Adds Debris and Contaminants to the Water

Dealing with rain getting into your pool is one thing, but dealing with all the extra runoff rainwater is another annoying hassle all on its own. If you’re looking at a massive rainstorm, water is going to gather on the concrete around the pool, on top of the house, etc.  

This water load is more than likely going to bring a lot of tiny, unwanted contaminants and debris into the pool that will later need to be removed. Always focus on removing the biggest pieces of debris you see. You do not want anything clogging your pump or filter.

 

Rainwater Effect #3 – Could Damage Pool Equipment

Acidic water can cause your pool water to corrode plaster and metal materials within the water, like handrails, ladders, and steel walls behind a vinyl liner. That is another reason why it is so important to monitor water chemistry before, during, and after a rainstorm to ensure that the chemistry stays as balanced as possible.

If you experience a heavy rainstorm and your pool is uncovered, it is recommended that you clean your filter afterward to clear out any buildup of debris or contaminants that may have entered the pool via rain and runoff water.

 

Rainwater Effect #4 – Can Raise Water Level

The recommended water level for an inground pool is about halfway up the skimmer face plate. A heavy rain pour can raise the water level above the proper height. If this happens, the pool is going to need to be partially drained back down to the correct levels. Draining the water will change the chemistry as well, requiring an adjustment. 

 

Conclusion

Dealing with the natural elements is just one part of maintaining a swimming pool. Rainwater is annoying, we get it, but a few simple steps can solve any problem that rainwater creates. Reminder: If you have a strong, durable cover or an automatic cover, always keep the pool closed during any rain to curb any potential damage that may come from rainwater. If you don’t have a cover, just remember to check the water chemistry as often as possible during rain time and make the proper adjustments when the rain has stopped. For more educational content on all things pools and landscaping, check out our learning center above. Below are a few articles to get you started!

Pool Water Test Strips vs. DPD Test Kits vs. Digital Water Labs: Which is Best?

How Often Do I Need to Get My Pool Water Tested?

How To Close An Inground Swimming Pool For The Winter