That's what I understand CC to mean also. Yesterday, when I asked the pool store girl if CC meant "the chlorine was currently working and still killing something then becoming unavailable to kill again" she told me no, that's not what it means. She couldn't explain to me why I wanted such a low or nonexistent CC level. One of us needs retraining.

But I still don't know how to increase the cl to a for-sure level of 30. Aside from the method I mentioned earlier, which is a best-guess scenario, how do I measure that high?