Not sure I'm following you... Do you mean I should read the oto test after 10 minutes and that should give a tc reading that will match immediate dpd results?
Also, I don't know if this adds another piece to the puzzle or confuses things further, but I just tested the CL again about an hour after adding 192oz of bleach. I pulled a sample from the pool in a measuring cup like I always do and ran the same dpd test 4 times with 4 completely different results:
1. Fc 5, when I added r-0003 for cc the sample turned a light yellow, not pink. I have had this happen once before, so I retested (assuming I did something wrong)
2. Fc 22, cc 1.5... Huh? Retest again...
3. Fc 7, cc light yellow/peach????
4. Fc 15, cc 7
All 4 tests were done within minutes from the same sample of pool water, and I rinsed with filtered water between tests. This stuff should be pretty simple, and I'm a pretty smart guy, but I am completely lost here.