Ideal calcium for a plaster or concrete pool is 200-400.
For a vinyl pool, 100 is fine--but was that a recent reading, done after the large amounts of cal-hypo that you used? As far as the DE goes, start with 1/2 cup into the skimmer and watch your pump pressure for a few minutes. If it rises to 1 psi, then stop. If you see no rise, then add another 1/2 cup, which will probably do the trick. If you get over 1 psi rise, then backwash it out and try again.

Janet