Skip to main content
Home & Garden

There’s a disgusting reason you smell chlorine at the pool

It's what you think it is

Recommendations are independently chosen by Reviewed’s editors. Purchases you make through our links may earn us a commission.

My father attempted to teach me to swim by throwing me into a lake. It didn't work. Then my mother signed me up for lessons at the local Y. For the next 10 years, I swam in that pool at least once a week, sometimes up to five times a week, first as a student and then as a competitor.

I still remember the smell, and how it came in waves. First, you'd get hit with a faint whiff of chlorine went you went down the stairs to the basement, and by the time you exited the locker room you could taste the musty air. What really struck me was during early morning training—you'd go in and not smell a thing until you hit the water. Years later, when I learned the disgusting reason why, it changed my perspective about swimming lessons, pool parties, and getting in the pool in general.

So why do you smell chlorine at the pool?

There should be between 1 to 3 ppm of chlorine, or 1 and 3 milligrams per liter.

It turns out that there's very little chlorine in pool water. The State of Indiana's Department of Health suggests only putting between 1 and 3 parts per million–less than a thimble per gallon. And pure chlorine is odorless.

What you're actually smelling are chloramines. One way these chemicals form is through a reaction with ammonia–which is found in body oils, sweat, and yes, urine. So the stronger the "chlorine" smell, the dirtier the pool is.

Gross! Does this mean you shouldn’t go in the water?

What you smell at the pool is actually the chlorine reacting to body soils.

Just because you smell chlorine, doesn't mean the pool is unsafe. However, there are signs that indicate that you shouldn't let your kids take a dip. Here's a quick guide to what you should always do before going in a pool.

Look: If the water looks cloudy or green, it's too dirty to swim in
Smell: If the water smell is stinging your nose, don't go in
Touch: If the walls of the pool feels slimy, there is too much bacteria growth

What should you do if your own pool smells?

If your pool smells, you may need to chlorine shock it.

The basic rule of thumb is to super-chlorinate–add extra chlorine to the pool to disinfect the disinfectant. You also need to shut down your pool for up to a day to let the chlorine levels return to normal. This time allows for the the water's pH to readjust.

Is there a way to prevent a smelly pool?

Aside from regular cleaning and maintenance, you should shower before entering the pool to wash off those body soils. Also, encourage your children to take frequent bathroom breaks.

Up next