You're getting good advice so far, I just differ in one area--I would not add the stabilizer until after your conversion is complete (i.e., you can hold a chlorine residual overnight). You want your chlorine to be at its most effective while you're burning off the Baq. So take your Cl back up to 10-15 ppm, and hold it there until it doesn't drop overnight.

As far as the dilution goes, you take one part (CarlD's shotglass!) pool water, and one part distilled water, mix thoroughly, run your test from that, read the results, and multiply by 2 to get your Cl reading.

Janet