Episode 12:Combined Chlorine and Chloramines: Why Your Pool Smells Like Chlorine When You Actually Need More of It | The Pools Scientific Podcast
If your pool smells like chlorine and your eyes are stinging, you've probably heard the same explanation everybody hears: too much chlorine.
That answer is backwards.
In this episode, John Cooper breaks down what's actually happening in that water. Free chlorine reacts with the nitrogen everyone brings into a pool (sweat, saliva, sunscreen, and yes, urine) to form chloramines. There are three of them, monochloramine, dichloramine, and trichloramine (also called nitrogen trichloride), and the last one is the compound doing the damage. It doesn't stay in the water. It leaves, right at the height of your nose and eyes, which is why that chloramine smell and the red eyes it causes are so much worse indoors and in a hot tub than they ever are in a backyard pool.
John walks through the real history behind this chemistry (a 1974 water treatment textbook, a case report that named a condition called lifeguard lung, and a CDC investigation into indoor pool air quality at a water park where the water tested clean the entire time) and a real field case from a Kansas City metro hot tub. He also explains why hot tub chemistry is the single most demanding body of water on your property, and why a clear hotel hot tub with a chemical smell isn't reassurance.
What you'll learn in this episode:
Why combined chlorine and trichloramine, not too much chlorine, cause that smell and the red eyes
The three chloramines and why each one matters differently
Why hot tub chloramine problems build faster than pool problems, and what that means for you
Why pool shock not working for long is the expected outcome, not a fluke
What to test for before you get in a hotel hot tub
Before next week: test your own water. If you don't have a good test kit, get one, and learn to use it. A combined chlorine reading above 0.5 ppm means chloramines are building in your water right now.
Next week: breakpoint chlorination, and why the number everyone's heard for it is wrong.
Full show notes and sources for this episode are at Poolsscientific.com.
Show notes and free resources at PoolsScientific.com. Subscribe to the weekly email list for episode updates. Ebooks available at payhip.com/poolsscientific. Follow us on Instagram @poolsscientific24. The Pools Scientific Podcast is produced by Pools Scientific LLC — Elevated Pool Care Through Science and Technology.