Hi, Boyd,

Wow! We finally got a nice name for poolidiot! (which you never were)

I'd do just like you're thinking.....Cl up to shock level, test, and if numbers are good, I'd backwash the sand filter one last time and then put the CYA in.

Dosage for CYA is on the container or you can get mwsmith2's calc and figure it yourself.

Whatever you did last Fall, I'd do again this Fall