Quote Originally Posted by fhorta View Post
... the "maintain shock level for 24 hours" ...
Not how we recommend shocking here.
Keep FC at or above shock level until one full day after these three criteria: 1)The pool loses less than 1 ppm between sunset and sunrise 2) The pool has 0.5ppm CC or less 3)The water is clear. With CYA 70-80 your FC to chock is 20ppm.

... Ph, alkalinity, calcium all are in range according to kit test results...
We can help you better if you give us the numbers.