As a homeowner, you know that great things often come with great responsibility. You want your pool to be a safe place to swim for you, your family, friends, and neighbors. So, it’s your job to ensure that your pool water chemistry is balanced.
Rain can significantly impact your pool’s pH levels, which can pose a threat to your swimming pool and all those who swim in it. That’s why it’s important to know what to do when storms come your way.
In this article, I’ll explain how rain affects your pool chemistry, what you should do to check your pool after it rains, how to prepare for the next rainstorm, and more. Let’s dive in!
How a Rainstorm Affects Your Pool Chemistry
Maintaining the balance of your pool chemicals is a recurring obligation. It’s essential to keep an eye on the pH, alkalinity, chlorine, calcium hardness, and other chemical levels to ensure a pleasant and safe swimming experience. And not to mention, a beautiful, crystal clear appearance!
Did you know that rainwater can cause chemical imbalances?
You might be thinking, isn’t rainwater pure? How could it damage my pool? Well, you’re partially right.
Rain starts at a pure, neutral seven ranking on the pH scale, a scientific scale that determines how acidic or basic (also called alkaline) water is. But as it’s released from the sky, it becomes polluted by the many different gases spewed into our atmosphere by industrial plants, fertilizers, car exhaust, and other human activities. The two most common gases are sulfur dioxide (SO2) and nitrogen oxide (NO2).
This type of rain is called “acid rain” and is dangerous for humans, the environment, and, you guessed it, your pool.
Acid rain has a low pH level (below seven), signifying that it’s highly acidic. The recommended pH level for a swimming pool is between 7.2 – 7.8.
What Happens When a Pool Has Too Much Acid
The more acidic the water, the more corrosive it becomes.
As the rain mixes with your pool water, it can begin to lower the pH level and cause your pool’s interior and exterior materials to deteriorate over time (here’s my guide on how to raise your pH level back up). This cutting process is often referred to as “etching,” which can also result from low calcium hardness and damage concrete, gunite, plaster, stone, tile, and other commonly used pool materials.
This increased acidity in a pool can also cause skin irritation for swimmers, along with red and itchy eyes.
What Happens When a Pool Has Too Much Base
On the other hand, rainwater can also dilute the pre-existing chemicals in your pool water and cause your pH levels to rise. When your pool water becomes too basic, it can cause “scaling,” or the build-up of calcium. These white, crusty scales often look like salt and form a gray film on the surface of your pool water.
Eventually, this can lead to other issues such as excessive algae, cloudiness, reduced water filtration, damage to your plumbing system, and rough walls. People who swim in overly basic pool water may experience skin rashes.
What You Should Do to Check Your Pool After It Rains
Now that you understand the impact rain can have on your pool water, what do you do when a rainstorm hits home?
Most of the time, a light rain shower will not disturb your pool water. However, heavier rains are a different story. To be on the safe side, make sure to test the water after any kind of rain. It’s best to check your levels immediately after it stops raining to ensure everything is still balanced. If you find an imbalance, you can adjust the chemicals as you see fit.
If your pool water turned cloudy, check out my article on how to clear cloudy pool water after rain for all the steps you should take.
Should You Shock Your Pool After It Rains?
While you don’t have to shock your pool after every sprinkle, it can still be beneficial. Pool shock is an efficient and effective treatment that can help keep your pool chemistry balanced and looking great.
Pool shocking is the process of over-chlorinating a pool for a specified amount of time to minimize chemical exposure and eliminate algae, bacteria, and other harmful contaminants.
Pool owners often use pool shock products after heavy use or when the water is contaminated somehow. It’s recommended to shock a pool after everyone is out of the pool and the sun has set so the shock chemicals won’t evaporate.
Some situations in which pool owners shock their pools include:
- Opening the pool for the first time in the summer
- After heavy rain or major storm
- After a large number of people have been swimming in the pool
- When temperatures are high for long periods of time
So, if you feel like you need to shock, go for it!
How to Drain Water From Your Pool After It Rains
You may be wondering if you should drain water from your pool immediately after it stops raining. Again, this depends on how much rain you receive.
Head outside and examine your pool water level to see what you’re working with.
Was it a minor shower or drizzle? If so, you probably don’t need to do anything but check the levels.
Or maybe you had an intense thunderstorm with heavy rain. Is the water noticeably higher? Are your skimmers completely submerged? Is water splashing out of the pool? In this case, you may need to drain some water.
Here are a few simple steps to start draining your pool.
Step 1: Clean
You don’t want any dirt or debris to fall into the water during the draining process. So, be sure to clean the area surrounding your pool (such as the patio or the deck) and remove any debris from the pool, skimmer, and pumps with a net or your hands.
Step 2: Start Circulating
Switch your pump and filter on to start circulating the pool water. This will eliminate any small contaminants that you may have missed.
Step 3: Suck It Up
Pull out your pool vacuum or turn on your automatic cleaner (if you have one) to remove all debris from your pool. Keep on vacuuming until the waterline reaches approximately halfway on the skimmer plate.
Step 4: Drain
Sometimes you can simply use your pool vacuum to suck up the excess water. However, sometimes this isn’t enough to do the job. In this case, you can use a backwash hose or sump pump hose to finish the task and get your waterline back to normal.
Step 5: Balance
Test your pool water to see if any chemical adjustments need to be made, and ensure that your pool does not turn green or cloudy. I recommend checking the pH, alkalinity, calcium, and cyanuric acid levels.
How to Prepare Your Pool For a Rainstorm
By now, you’ve lived and learned. Save some time and effort after the next rainfall by learning how to prepare effectively.
Here are several things you can do beforehand to prevent the amount of work you have to do after the storm has passed.
- Make sure to remove all deck or patio furniture and pool accessories from the area surrounding your pool before the storm. Doing so will prevent anything from falling into the pool, blowing away into neighbors’ yards, and causing damage to both your pool and furniture.
- Turn off and cover all of your pool equipment (motors, filters, heaters, lighting fixtures, pumps, etc.) to avoid any electrical issues or damage during the storm.
- Detach all gas lines from pool heaters to protect you and your family from any sort of dangerous gas leak, deadly carbon monoxide poisoning, or fire.
- Balance your pool water before the storm hits to help combat pollutants. This will make for a more straightforward, painless post-storm clean-up and balancing.
- Don’t drain your pool water before a storm, as this leaves the walls and floor vulnerable to damage (especially during high winds).
- Try to trim tree branches in your backyard to minimize the possibility of them being thrown into your pool.
Get My Free Pool Care Checklist
Download my free, printable pool maintenance checklist to help you accomplish regular pool care tasks for any type of swimming pool.
Enjoy a Safe Swim in a Balanced Pool
You don’t have to be a chemistry wiz to understand how to keep your pool’s pH levels balanced. With a little practice, patience, and this newfound knowledge, your pool will be the neighborhood hotspot!
Watch the weather for rain and storms, so you know when they’re on the way. Observe the appearance of your pool water, as this is often a tell-tale sign of a chemical imbalance. And make sure to frequently test your pool water levels (whether it rained or not) to protect you, your pool, and your loved ones.
Now that you know what to do after the rain is gone, get out there and enjoy some fun in the sun!
Questions? Let me know.