After living with pools for over 40 years (one at my parents house and I have owned three), I am about to become a BBB convert.
It was actually the experience with CYA that pushed me over the edge. I had no idea what "too much" CYA meant until I had a guy at Leslie's explain it to me.
The Leslie's guy told me that CYA tends to float in the water, so it's best to drain off the top. I have a portable sump pump and have been setting it on my stairs, starting at the top, to maximize my removal.
My level is over 100, so I am draining off a bunch of water. Maybe half the pool...
Many more questions to come, got my test kit in the mail last week.