Howdy. Great place for great information (still - see postscript)
I'll try to keep this as simple as I can.
My tests this AM gave me the following (Taylor K2006).
pH 7.8
FC 4.4
CC 0.2
CYA 0 (at least, no reading)
TA 290

I've added 3 cups of muriatic acid about 3 hours ago.

I'm wondering about the CYA. I have 25 lbs of 100% CYA but wonder if and how much I should add.
Also, when should I check the pH again?

The pool is clear with no sign of algae.

Thanks for any and all help.

P.S. even though I just joined yesterday, I'm unable to post in the getting started area. Not that it matters, but I was a member many years ago. I don't recall the username I used.