Testing with high TC

[polyvue]

Thanks Anna! I guess unless someone like Chem Geek tells me otherwise, I'll have to assume that I can't do any other tests when shocking.

I don't know... I've tested pH and gotten reasonably accurate results at a shock level of ~12 PPM Free Chlorine. Lack of precision in color matching (interpretation), variations in (test tube) sample volume and titration can work together to exaggerate an error; they can also work to cancel each other out. Some tests, as AnnaK alludes to, above, commence with chlorine neutralizer (thiosulfate, in the tests I have) so you should be able to add an extra drop or two and correct for that. Don't try this with the pH test, however. In general, it's best to adjust pH before shocking to high levels (above 10 PPM).

I'm not aware of any interference from high chlorine levels with the Calcium Hardness or Cyanuric Acid test. Has anyone else encountered this?