Thanks for the info about the CYA. I'm learning so much.
The numbers from the pool store are:
ph - 7.2
ta - 90
cya - 0
tc - 0
fc - 0
(I've learned the other numbers aren't important since I have a vinyl pool, 18 x 38 w/deep end).
The chlorine was way above 5 yesterday morning and the ph is about the same.
Thanks sooo much for the help.
Kerrie