That strong chlorine smell means your pool needs more chlorine.

No, that strong smell is not a sign of too much chlorine — it’s a sign that the chlorine has already been used up and turned into chloramines.

Here’s the chemistry: when chlorine kills bacteria, oils, and sweat from swimmers, it transforms into chloramines. Chloramines are what you smell, and they’re also what sting your eyes. They’re less effective at sanitizing than free chlorine. So a strong “chlorine smell” actually means your pool is dirty and under-chlorinated.

It’s not exactly dangerous in the sense of poisoning, but it can irritate your lungs and eyes, especially in an enclosed pool area. If you’re swimming in that soup, you’re also swimming in the stuff the chlorine already killed. Not ideal.

Fix: shock the pool (raise free chlorine to 10x the combined chlorine level), run the pump, and let it burn off the chloramines. The smell will vanish in a few hours.

Your nose is lying to you. Trust the test kit instead.