The wildfires in Canada are at it again — creating dense layers of smoke that continue to drift over large swaths of the U.S. This smoke has lowered air quality to dangerous levels across the northern part of the country, impacting more than a third of the population.
In addition to the health dangers this type of air pollution poses to humans and animals, wildfire smoke poses a threat to your pool’s health, too. Smoke and other forms of air pollution affect the water chemistry and can make it challenging to keep your pool safe and enjoyable for swimming.
Below are five steps you can take to protect your swimming pool from excessive smoke pollution:
#1 Keep your pool’s filter pump running until the smoke has passed.
Sufficient water circulation is important to your pool’s health. As the water circulates, harmful contaminants get trapped and removed by the filter system. Running your pool pump for 8–10 hours or more per day ensures your water doesn’t become stagnant and accumulate debris. When you can smell and see smoke in the air around your property or community, keep the filter pump running 24/7 until the smoke is no longer present.
Important Note: Running the pool pump can cause debris to pile up in the skimmer and pump baskets, so make sure to clean these out when conditions are smoky to ease the workload on the pump system.
#2 Test, balance, and shock your water to correct issues caused by the smoke.
Running the pool pump also helps distribute pool chemicals throughout your pool. Wildfire smoke often carries microscopic particles of nitrates, phosphates, ammonia, and other organic and inorganic compounds that can alter your pool’s water chemistry. Excessive amounts of this tiny debris can wreak havoc on your pool’s sanitizer levels, rendering the water unsafe for swimming.
Contaminants and nitrogen-based compounds, such as ammonia, from wildfires can also create a water chemistry imbalance in your pool. These contaminants quickly consume Free Available Chlorine (FAC), which is the amount of chlorine available to eliminate harmful microbes and neutralize contaminants.
Water testing is crucial, and during typical swim season conditions we recommend weekly comprehensive pool water testing to get detailed insights into the water chemistry. Knowing your pool’s water chemistry is an important step to assess its condition before embarking on a course of treatment. During times of wildfire smoke, testing may need to be more frequent, even daily to address issues. While you can use at-home test kits or test strips to measure basic aspects like pH and FAC levels, these tests aren’t comprehensive or always precise. Pool stores like Leslie’s offer comprehensive, in-store water testing. Leslie’s free AccuBlue® water test — available at more than 1,000 store locations — analyzes 10 water chemistry elements in just 60 seconds, and provides a water health score and an easy-to-follow customized water treatment plan for your pool based on the test results.
#3 Maintain proper Free Available Chlorine (FAC) and pH levels.
FAC is the sanitizer for your pool water and it kills harmful contaminants. Monitoring the FAC levels in your pool is important. If you test your pool’s water during and after periods of heavy smoke, chlorine levels may be low or nonexistent. If so, superchlorinating your water with a quality chlorine pool shock is recommended. This will both increase FAC levels and eliminate the contaminants creating high chlorine demand. You may have to boost chlorine levels for 24–48 hours to rid your pool water of all contaminants.
The pH level is key to your pool’s health and impacts the effectiveness of your chlorine sanitizer. Your goal should be to keep your pool’s pH level between 7.4 to 7.6. Pool water pH above 7.6 is alkaline and diminishes the effectiveness of chlorine, while pH below 7.4 is acidic and may accelerate the speed of chlorine dissipation. Other problems arising from imbalanced pH include cloudy water, stains and scale (the buildup of calcium carbonate on pool surfaces and walls), and corrosion of pool surfaces and equipment.
Residue from smoke is normally acidic and thus will lower your pool’s pH level. There are pool chemical products just for this specific need called “pH increasers” that restore pH in pool water. Some smoke compounds, however, will increase pH; in those instances, you can use dry acid or muriatic acid to lower pH back to its ideal range.
#4 Add specialty chemicals to expedite pool water recovery efforts.
Wildfire smoke can deposit all sorts of contaminants into the water, including phosphates, fine soot, and organic debris. Putting a few specialty chemicals into the water can help expedite your pool recovery efforts and prevent bigger problems. These include:
Phosphate removers. Phosphates are a primary food source for algae. The lower the phosphate level, the less likely algae will take over your pool. If your water test shows phosphate levels above 100 parts per billion (ppb), a phosphate remover can get this situation under control.
Enzymes. These chemicals target non-living organic contaminants in your pool water deposited during high-contamination events, such as smoke pollution from wildfires. A broad-spectrum enzyme treatment can help your pool recover more quickly. Keep in mind, though, that chlorine levels must be below 5 ppm when using enzymes, or the chlorine will attack the enzymes instead of the contaminants.
Clarifiers. Even if you run your pool’s filter pump 24/7, fine soot and ash from the smoke can still make it through the filtering system and cause cloudy water issues. A water clarifier can remove this debris by clumping together fine debris into larger groups that can be more easily trapped and removed by your pool’s filtering system.
If you’re also dealing with cloudy water issues caused by fine, ashy debris, a treatment that contains both enzymes and a water clarifier is often recommended.
#5 Clean the pool filter as needed to maintain clean and clear water.
All the soot, ash, and other debris deposited by heavy wildfire smoke can quickly fill up your pool filtering system, especially when the pump is running 24 hours a day. Clarifiers also trap the extra-fine debris in the water, putting more burden on the filter. It’s important to stay on top of cleaning out your skimmer and pump baskets, as well as cleaning the filter media according to the manufacturer’s instructions.
Your pool is both an investment and an oasis of enjoyment for your family and friends. By following the steps outlined above, you can protect your pool’s water from the damage caused by wildfire smoke.
Alicia Toedter is head of pool care education and content at Leslie’s, the largest direct-to-consumer brand in the U.S. pool and spa care industry.