When Should I Worry About...

Should You Be Worried About Germs in Your Swimming Pool?

May 4, 2020 - Katie McCallum

Summer is finally here, and you probably feel like you've been ready for pool season for months. But, before you and your family dive in, are you sure your swimming pool is ready for pool season, too?

Germs can be found almost anywhere, including in swimming pools and hot tubs. This means that proper cleaning and maintenance of your pool and hot tub are essential to preventing getting sick while swimming.

How the water in your pool can make you sick

Recreational water illnesses are infections caused by germs that can survive and/or grow in swimming pools, hot tubs, oceans, lakes and rivers — as well as in the water at water parks and splash pads. These illnesses are spread by either swallowing, coming into contact with or breathing in aerosolized mists of germ-containing water.

According to the CDC, most recreational water illnesses are caused by the water contamination that occurs when someone who is ill and carrying germs enters a pool. In other cases, these illnesses are caused when germs that naturally live in water grow to levels that can cause an infection.

Common types of recreational water illnesses include:

  • Diarrheal infections
  • Skin infections, such as "hot tub rash"
  • Swimmer's ear
  • Respiratory infections caused by breathing in a mist of germs, usually while in a hot tub

The most commonly reported recreational water illness is diarrhea — often caused by germs such as E. coli, norovirus and Cryptosporidium (also referred to as Crypto). When a person with a diarrheal illness enters the water, the entire pool can become contaminated. In turn, swallowing even just a small amount of this contaminated water is enough to result in illness.

While this may sound scary, your risk of getting a recreational water illness is greatly reduced if your pool is properly maintained and you and your family take steps to swim safely.


Prevent illness by maintaining proper chlorine and pH levels

Proper pool maintenance is more than just skimming leaves and brushing away algae. It's regularly checking the chlorine level and pH of your pool — especially during the times your pool is most frequently used.

When chlorine is mixed with water, it creates a "weak" acid that's ideal for killing many types of germs. It's why we use chlorine as a disinfectant in our pools and hot tubs. The CDC recommends a free chlorine level of 1 ppm for your pool and 3 ppm for your hot tub.

But, the pH of your pool matters, too. Chlorine only works well if the pH of your pool falls within the right range. If the pH of your pool is too high (above 8), chlorine is much less effective at killing germs. On the flip side, if the pH is too low (below 7), it can cause pipe corrosion. The CDC recommends keeping the pH of your pool between 7.2 and 7.8.

Other factors affect chlorine, too. Any dirt, sweat, pee or poop in the water is broken down by chlorine — using up chlorine and reducing the chlorine level of the pool or hot tub. In addition, high temperatures (think, hot tubs), sunlight and any water feature or jets that aerosolize water or create mist also use up chlorine.

This means that it's important to regularly check both the chlorine level and pH of your pool. When both chlorine and pH are maintained at the right level and range, the result is a perfect balance between germ-killing and pool-system longevity. In addition, this range reduces skin and eye irritation that can occur at both a very high or a very low pH.

One thing to note, however, is that chlorine doesn't immediately kill germs. While it can kill most bacteria in less than a minute, other germs are more chlorine-tolerant. For instance, one of the common causes of recreational water diarrheal illness, Crypto, can survive as long as 10 days in a properly chlorinated pool.

This is why it's also important to take steps to swim safely — whether its in the swimming pool in your backyard or one shared by an entire community.

Tips for swimming safely

To help protect yourself and your family from germs that may be in a swimming pool, follow these tips:

  • Make sure the pool is regularly cleaned and properly maintained. If you're a pool owner, be sure you're keeping tabs on your pool's chlorine level and pH. If you're using a public pool, ask for the pool's inspection scores, or look them up online. In addition, pool supply stores, and even many large supermarkets, sell test strips that you can use to test chlorine and pH levels yourself.

  • Don't swim if you're sick. If you (or your child) have diarrhea or are recovering from diarrhea, avoid spreading germs by getting into a pool.

  • Know how to handle a fecal incident. If you're a pool owner, follow proper pool cleaning and remediation techniques when removing poop or diarrhea from your swimming pool. If you're using a public pool, alert the pool staff or lifeguards of any fecal incidents immediately.

  • Take a quick shower before you swim. It's tempting to think of a pool like a bath, but even just a quick rinse before getting in a pool can reduce the amount of dirt and sweat you bring into the water — which, in turn, can help maintain proper chlorine levels.

  • Dry your ears when you get out. To prevent ear infections that occur as a result of leaving contaminated water in your ear, make sure to thoroughly dry your ears after getting out of the pool. If you have a history of ear infections, consider wearing a swim cap or ear plugs.

  • Prep your kids. Before it's time to swim, remind your kids to avoid peeing in the pool or swallowing pool water. For younger children, schedule bathroom breaks and diaper changes every hour — making sure to change diapers in a bathroom, not poolside.


In addition to these tips, always remember to stay safe at the pool by preventing slips, trips and falls, supervising children and having small children or adults without adequate swimming skills wear a life vest. It's also important to practice sun safety when at the pool — frequently and thoroughly applying water-resistant sunscreen, as well as using other methods to protect yourself from the sun.

Stay up-to-date
By signing up, you will receive our newsletter with articles, videos, health tips and more.
Please Enter Email
Please Enter Valid Email
Categories: When Should I Worry About...