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, at the top of the list you should filter the water and take a sample into your local Irribiz, Total Leisure or Pool Store, to test especially the pH, alkalinity and sanitiser levels.
1. Clean The Pool
Sometimes after it rains, you will find winds have blow a lot of dirt, leaves and other debris in your pool. This often increases the nitrogen and phosphorus levels promoting growth of algae and bacteria.
First, skim your pool, then vacuum. You can use an automatic pool cleaner or manually 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 sanitiser level might be low as well. So be sure to check these levels.
4. Check Your Water Level
Of course, after it rains you will have more water in your pool than what’s needed. If you have an excess of water in 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 sanitiser 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.