Whether peeing in a pool changed the color of the water has been asked for a long time and there are have been many supposed answers to this question of “Does Pee Turn Blue In Swimming Pools?”.
Some people have said that pee turns the water blue, some say it turns green, but they all agree that if you swim in a pool with pee in it, your urine will change the color of the water. There are some other reasons (outside of urine or a chemcial) that would cause your pool water to be green however.
But is this all just a myth? Is there a special Urine Detector chemical for Swimming Pools? Is it an urban legend to keep kids from peeing in the pool that still rings true to this very day? And if it isn’t true, where on earth did the idea come from?!
The short answer is No, one child peeing in a normal sized inground or above ground swimming pool will not change the pool water color in any dramatic or noticeable fashion.
However, there is some science that backs certain amounts of urine changing the color of swimming pool, so we are going to be looking at the claim that urinating in a pool will change the watercolor, the origin of such a claim, and finally, whether it is somewhat fact or fully fiction. Lets dive in!
Table of Contents
What Is The Claim?
The claim is that when peeing in a pool, the surrounding water will turn blue (or another color), thus exposing whoever has urinated.
It is said that chlorine water has a special chemical compound that has been added to react with urine in the pool water, changing the color. But does pee have any effect on the color of the water?
What Is The Origin?
Where did this urban legend come from?
What is the origin behind the story?
According to Urban Legends Reference Pages, the first reference to the pee-turns-blue myth was in a book called “Swim Safely” by Robert M. Fenton.
This book was published in 1976, so we can assume that this myth was born sometime between then and now.
However, the author of the book claims that he heard about it from his father, who supposedly told him that it happened during World War II.
He also says that he heard it from his grandfather, who allegedly told him that it happened in the 1920s. So, as you can see, there are a lot of stories and hearsay surrounding this myth.
But if it is a story, why make it up in the first place? Most people say it is to stop people from peeing in the pool.
Because the water would change, you would be exposed to urinating and that would be embarrassing for everyone involved.
So, perhaps this myth was made up simply by parents who didn’t want their kids peeing in the swimming pool.
What Is The Truth About Pee Changing Swimming Pool Water Color?
Let’s take a look at the evidence. There are two main theories about how pee changes the color of the water in swimming pools.
One says that the chemicals in urine cause the water to become blue, while the other theory says that the chemicals in the urine causes the water to turn green.
Both of these claims can be backed up by scientific studies, so let’s take a look at both sides of the argument.
The first study was done in 1973 by Dr. David H. Miller, Ph.D., a professor at Texas A&M University. He studied the effects of urine on swimming pools and concluded that urine did not affect the color of pool water.
His research showed that the only way to make the water change colors was to add chlorine to the water. This means that his findings support the theory that adding chlorine causes the water to change color.
Another study was conducted by researchers at the University of Florida. They found that the addition of urine to the water caused the water to turn green instead of blue.
Their research also supported the theory that the addition of chlorine causes the water to turn blue.
Now, I know what you’re thinking… If the color of the water turns blue, doesn’t that mean that someone peed in the pool? To answer your question: not necessarily.
According to the National Association of Pool Safety Professionals, the color of the water could just be because the pool has too much chlorine in it.
Chlorine is used to kill bacteria in the pool, which leads to a white or yellowish tint in the water. When the chlorine levels get high enough, the water starts turning blue. Use a quality pool chorine tester to check your swimming pool’s chlorine levels at any time!
So, if you have a pool with a very high level of chlorine, you may notice that the water turns blue even when nobody pees in the pool!
So, let us get down to the bottom line here. Is pee turning the water blue a real thing? Or is it simply a myth that has grown over the years?
Let’s take a look at what science has to say about the matter. According to Wikipedia, the answer to our question is yes and no.
Yes, pee can slightly change the overall color of the pool water, but only if you have a high concentration of urine in the pool.
If the concentration is low, the water won’t change colors. Also, the amount of time it takes for the water to change depends on how much urine is present in the pool.
If there is less than one part per million of urine in the pool, the water will stay clear. If there is more than one part per million, the water will start to turn blue after a few minutes.
If there are more like two parts per million, the water may turn green after a couple of hours.
So, the truth is that peeing in the swimming pool will change the color of your pool water, but not always and not necessarily right away.
Essentially, there would need to be an unusual amount of urine in the pool for the color to noticeably change.
There isn’t, however, any special compound or Urine Detection chemical that exists today that will change the color of the pool water when mixed with urine.
Final Thoughts on How Urine Affects Swimming Pool Water
To conclude our initial question of “Does Pee Turn Blue In Swimming Pools?”, the claim that peeing into a swimming pool will change the color is a myth. However, the myth is based on some fact because the color of the pool will change if there is a large amount of urine in the water.
And even though the swimming pool water color changes, it doesn’t happen immediately. It could take anywhere from a few seconds to several hours before the color starts to change.
As it turns out, your parents have been lying to you this entire time! Your pee will not single-handedly change the color of the water of the pool that you are in! However, there are many reasons to still not pee in the swimming pool, mostly related to the health and sanitation of everyone using it.
Hi, I am Victor, co-owner of All About Pools and an expert on swimming pool equipment and machinery. I have a degree in Business Marketing from the University of Missouri-Kansas City and my hobbies include lacrosse, teaching swimming, graphic design, diving, traveling, and going on hikes with my two dogs.