Normally, you want your CC level to at or below the lowest reading on your chlorine test. So, if you are using the FAS-DPD at the 1 drop = 0.5 ppm dilution, than you want a CC of 0.5 or less. If you are doing the 0.2 ppm dilution, than you want 0.2 ppm or less.

CC is chlorine that attached goo -- usually people goo -- but didn't finish the job. On an outdoor pool exposed to sunlight, you'll rarely have significant CC levels if
1. you chlorinate CONSISTENTLY;
2. you don't add pool store goo;
3. you haven't just had a ginormous pool party, with all sorts of people getting lotion or pee in the pool.

But, during start up, things are different. I could explain more, but it would probably just be confusing. Just add the borax and bleach and keep using the tabs, and let us know what's going on, every couple of days -- unless something goes wrong. You *should* see a clearing pool, rising FC levels, and dropping CC levels.