how much shock is too much?

[justgrapejuice]

You are confusing the best guess table with bleachcalc. the best guess table is here
http://www.poolforum.com/pf2/showthread.php?t=365
Bleachcalc will not work on a mac.

Since there is not a Bleachcalc for a Mac, is there something that I can use to determine my needs?

Oh, BTW thanks for the best guess table info.