Aim for a shock level of 15ppm. In a 30K pool, each of the 121-oz. jugs will add approximately 2.5ppm of chlorine. Use that as a reference to help you figure out how much bleach to add each time you test. If your power stays off for awhile, you can continue to add bleach and just stir it around with a clean broom, etc. I lost power for a full week a couple of years ago and maintained my pool by doing just that -- adding bleach daily and stirring it around.

http://pool9.net/cl-cya/