That “chlorine” smell comes from chloramines: chlorine that has already reacted with sweat, urine and other waste. Test kits show them as combined chlorine (CC). A strong smell usually means there is too little free chlorine, not too much.
What to do
- Test free chlorine (FC) and combined chlorine (CC).
- If FC is below your target for your CYA, raise it.
- If CC is above 0.5 ppm, run the SLAM method until it is 0.5 or less.
- In hot tubs, leave the cover open for a while after soaking, and change the water when it stays smelly.