High chlorine interferes with PH test?

[Rangeball]

Isn't that what the "chlorine neutralizer" drop is for before you add the PH test stuff?

[JohnT]

Yes it is, but all kits don't have that, and it isn't perfect.

[waterbear]

The best reagents can only neutralize the chlorine to about 15 ppm. the sodium thiosulfate (chlorine neuralizer) itself can raise the pH and give inaccurate results if too much is added..