What You Should Do to Your Pool After it Rains

Often people ask us, “is there anything I should do to my pool after it rains?” It’s a very common question, and there are a few things you should check after a heavy rain.

Rain can sometimes affect your pool’s water chemistry. Because rain water can be acidic, it can affect your pool’s pH balance. After a heavy rain, you also have a lot of extra water in the pool that can dilute the chemistry.

If you get some light showers, I wouldn’t worry too much about the pool chemistry. A light rain will have very little effect, if any, on your pool water. However, it wouldn’t hurt to do these checks anyway, if only for good measure.

After a heavy rain fall, the first thing you should do is clean the water and check the water chemistry with test strips, especially the pH, alkalinity and sanitizer levels.

1. Clean The Pool

Sometimes rain comes with heavy winds, and winds can blow a lot of dirt, leaves and other debris in your pool.

First, skim your pool, then vacuum. You can use an automatic pool cleaner ormanually vacuum the pool yourself. Once your pool is cleaned, you can test the water chemistry.

2. Check pH and Alkalinity Levels

Acid rain can cause your pH to drop. However, this is what alkalinity’s job is.

When rain tries to lower the pH, the alkalinity will take the big hit. That means, your alkalinity levels might see a more drastic change than your pH levels, which is a good thing — thank you, alkalinity.

3. Check Sanitizer Levels

You also want to check your chlorine or sanitizer levels. Rain can often introduce contaminants to your water, and your sanitizer will start fighting them off — thank you, sanitizer.

That means, your sanitizer level might be low as well. So be sure to check these levels.

4. Check Your Water Level

Of course, rain will add more water to your pool than what’s needed. If you have an excess of water to your pool, you can drain it a little by using your filter’s “waste” setting. Just let the pool drain until it’s back at the normal level.

You won’t need to worry too much about your calcium or CYA (cynauric acid) levels — these are not greatly affected by the rain besides dilution.

Should I Shock My Pool?

Shocking your pool isn’t necessary, although, it’s not a bad idea either. If you get an extremely heavy rain fall, you could shock your pool for good measure. This will help fight off any contaminants that the rain may have brought to your pool.

Just make sure you drain the water to the correct level, check your pH, alkalinity and sanitizer levels, then shock in the evening after the rain has ended.

Additional Information and Final Note

Of course, you should avoid swimming in your pool during an thunderstorm because of lightning, and you should probably just avoid swimming during the rain for this reason alone.

Run off from your pool deck may also bring in some contaminants from your lawn or the deck itself. Again, make sure you follow this checklist after a heavy rainfall and your pool wont’ have any issues including, cloudy water or algae.

Happy Swimming!

Visit our website to start weekly pool service after some heavy rain! 

The Blue Lagoons