How to Clear Cloudy Pool Water After a Rainstorm

Written by Michael Dean
November 16, 2023

clearing cloudy pool water after a rainstorm

After a rainstorm, all swimming pool owners have to deal with the aftermath of cleaning the pool. While dirt and debris are usually pretty easy to clean up, some pool owners also need to deal with cloudy pool water after a storm. In this article, I will explain why your pool is cloudy after rain, provide a guide for clearing your pool before and after a rainstorm, and answer some frequently asked questions.

Main Takeaways

  • Pool water can become cloudy because of dirt and debris, pollutants in rainwater, imbalanced pool chemistry, and changes in chemical levels.
  • You can clear cloudy pool water by running your filter, using a pool flocculant, and manually cleaning the pool.
  • Minimize the chances of a cloudy pool after a storm by using a pool cover and stormproofing your pool area before the rainstorm arrives.

Why is My Pool Cloudy After Rain?

There are two main reasons your pool water is cloudy after rain.

Rainwater Contains Pollutants, Dirt, and Debris

Rain collects a lot of unwanted elements as it passes through our atmosphere. Smoke, chemicals, fertilizers, factory pollutants, dust particles, bacteria, and various other contaminants, increase the acidity of the rain. So by the time the rain hits your pool, each droplet delivers a small dose of impurities and foreign chemicals to your water. And a storm comes with lots of downpour; the effects are multiplied.

During a major storm, the influx of debris and dirt that is carried into the pool by the rainwater can also include leaves, branches, and other organic matter. These, along with the pollutants in the droplets themselves, cloud the water and make it dirty and unclear.

Rainwater Disrupts PH Balance and Water Chemistry

The natural consequence of foreign materials entering the pool is a complete upheaval of your pool’s water chemistry and pH balance. Every pool owner understands the need to look after the chemistry for a hygienic swim session. And since rainwater is acidic, this can severely mess with the pool’s pH balance. It can cause the pool water to become cloudy as the alkalinity levels are disrupted.

Heavy rainfall can also dilute the chlorine levels in the pool, making it more challenging to maintain clear and clean water. Similarly, it can reduce algaecide or cyanuric acid levels, making your pool more vulnerable to algae bloom infestations.

To put it simply, rainstorms can cause a shift in the balance of chemicals in your water, which makes the water look cloudy and unclear.

Step-By-Step Guide: How to Clear Cloudy Pool Water After a Rainstorm

If you’ve recently had a rainstorm and your pool water has become cloudy, you need to take some quick action to prevent the water from getting worse. Here’s my step-by-step guide on how to clear your pool after a rainstorm. I also have advice on what to do if you have a cloudy saltwater swimming pool. Let’s get to those steps, though.

Step 1: Drain the Excess Water

If your pool is overflowing, you must lower the water levels before proceeding. You could use a submersible pump or, if it’s a small amount of extra water, a pool vacuum. Some pools also have features that automatically drain excess water.

Step 2: Test and Balance the Water

Following the storm, the main chemicals you need to test and balance for are pH, which ideally needs to be between 7.4-7.6, and alkalinity, which needs to be between 80-120 ppm (parts per million). You then need to check for calcium; both an excess or shortage of calcium can cause cloudiness and corrode pool plaster and equipment. The recommended range is 200-400 ppm.

Next, check your chlorine and cyanuric acid levels, which should ideally be between 1-3 ppm and 30-50 ppm, respectively. Shocking the pool is an excellent option if chlorine levels are really low.

Step 3: Turn On Your Pump

After you have balanced the water, turn your pump on and let it run for the next 12-16 hours to clear out all the particles and bacteria following the rain. This is especially important if you’ve shocked the pool or added other chemicals since you need the water to circulate. You should also run your pump during a rainstorm.

Step 4: Empty Your Skimmer Basket

While the pump’s running, do a general check of your skimmer equipment and empty the basket if it’s clogged with leaves and twigs. Skimmers can quickly accumulate organic matter after a big storm, so be sure to empty it.

Step 5: Clean the Water

Roll up your sleeves and get a skimmer net to help manually pick up any additional dirt and debris floating around the pool. While cleaning and eradicating the finer particles in the pool is best left up to the pump and any sanitizing chemicals, manually clearing the swimming pool of larger objects can help speed up the process. Also, use a pool brush to thoroughly clean the walls and dislodge any algae that might be trying to take root. After brushing the walls, vacuum the pool.

Step 6: Use a Flocculant

If your pool is still not as clear as you’d like it to be, use a flocculant to clump all the tiny particles so that all the unwanted debris is easier to clear up.

BioGuard Powerfloc

This solution from BioGuard is really effective and is what I use when I need a powerful flocculant.

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Once you’ve followed these points, your water should look clean and blue again. If cloudiness persists after 3-4 days, try shocking your pool.

How To Prep Your Pool For A Big Rainstorm

If you know a storm is approaching well in advance, this is your chance to take a few steps to minimize the impact the rainstorm will have on your pool:

Balance the Pool Water

By balancing the chemistry beforehand, your pool water will have the strength to fight off the impending pollutants that will fall in once the rainstorm hits. Doing so will make the cleanup process much easier after the storm, as your chemicals shouldn’t be too out of wack!

Stormproof the Surrounding Area

If you have deck chairs, hanging lights, or any other decorative elements around your pool that might get destroyed, move them to a safer area, such as the garage or shed.

Lower Water Levels

Before the rainstorm hits, lower the water in your pool roughly by a foot. This might help reduce the overflow and subsequent backwash of dirt and debris. Do not completely drain your pool!

Shut Down Equipment

Shut down and disconnect your pool equipment to avoid anything shorting or sparking. Any pool equipment still running might get damaged when the weather is bad. Additionally, remove any other equipment from around the pool, such as a robotic vacuum cleaner or a submersible pump. Stash them safely in your shed until the storm passes.

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.

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Frequently Asked Questions

How long does it take to clear cloudy water?

This can vary depending on several factors, such as the size of the pool, the amount of debris in the water, and the condition of the pool’s filtration and circulation systems. I’ve seen pools take anywhere from a few hours to a few days for the water to clear. If the pool has a good filtration system and the water is only slightly cloudy, a day could be enough to clear the water. On the other hand, if the water is really dirty, cloudiness could persist for several days.

Can you swim in cloudy water?

It is not advisable to swim in cloudy pool water. The water needs to be properly sanitized and balanced before use.

Is cloudy pool water after a rainstorm harmful?

Cloudy pool water may not be directly harmful, but with unbalanced chemical levels, the water could cause minor health issues to swimmers. There have been unpleasant cases where people get serious flu infections or a UTI following a dip in cloudy pool water following a rainstorm. At the very least, your skin and eyes may be irritated.

Will a cloudy pool clear on its own?

A cloudy pool would need a little help to clear up. You will need a functional filter, correct chlorine levels, and balanced water. Once that’s done, it should clear up on its own; however, if you continue to face problems, speak to an expert to figure out the best solution.

And that’s about it for this topic. If your pool water is turning green, too, check out my article on how to clear a green pool after rain. Have questions about cloudy pool water or other pool maintenance tasks? Let me know; always happy to help.

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