Thank you so much for taking the time to explain that. Makes perfect sense!

I kinda screwed up as I ran out of titrating reagent this morning BEFORE I could test. Should have been paying attention to that... I ran to the store and got distilled water to test that way. My best guesstimate using distilled water testing is that FC is at least 15. I actually did test FC before I added bleach last night so I could be fairly accurate with Pool Calculator calculations but then ended up adding a total of 5.5 gallons of 6% because that's what Janet said to do (and now I understand why). So, last night, FC should have been at about 21.5. All that to say that I think FC is at least 15 now. So, should I add more bleach now for insurance? If so, how much? Should I be testing pH when I test FC?
Thanks!!!