Yeah, you make a good point. I'm going to do it all in one shot.
I didn't calculate 2x more, but definitely more.
Since my CYA is 160 and it will take 24 hour to exchange 50% and get to a CYA of 80, if I stopped at 12 hours, now my CYA is 120. If I then allow the pool to mix, now I have to...