Sorry - just getting back here today - been busy.

So, I will do this tonight - with the only change being that I do not have 6% bleach on hand but have 12% liquid chlorine. Not sure I'll get an answer from you before I do this - but my guess is to add half a gallon of the 12%. If that's wrong, let me know.
Then I will turn off - and I assume leave off all day tomorrow.
Tomorrow evening I will test. You say to add more chlorine if it is below 10 ppm but not turn pump on.
(But I feel the pump should be on when I add the chlorine & then I will turn off? Please advise.) [ <= YES, pump on - PoolDoc; further response later ]
Will then let you know what it looks like on Wednesday.

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Forgot to answer your last question - yes, I have a full manual vacuum system & I am able to vacuum to waste.