pH and Chlorine

[no-mas]

Hello Friends -
At what point does chlorine have an effect on pH measurements? My current FC is 17.5, and pH measures 8.2, and I'm wondering at what level of chlorine can I trust my pH measurement before I adjust with MA.
Thanks...

 

[reebok]

above 10ppm fc makes ph read falsely high.

 

[no-mas]

Thanks Reebok.