High pH isn't safe for swimming, and neither is low pH.

No. Ideally 7.4 to 7.6, but anything from 7.2 to 7.8 is okay if you’re careful.

High pH (over 8.0) makes chlorine less effective, so bacteria and algae can grow. It also can cause skin rashes, eye irritation, and scale buildup on pool surfaces. Not dangerous in an emergency, but definitely not smart to swim regularly.

Low pH (under 7.0) is worse — it eats at metal fixtures and irritates skin and eyes. The ideal is right in the middle: 7.4-7.6. That’s where chlorine works best and the water feels neutral.

If your pH is off, adjust it before you swim. A few hours with the pump running and some pH decreaser or increaser does the job. Your skin and your pool equipment will thank you.