I've searched for the answer to this question but can not find it. I've been reading the "SHOCK YOUR POOL" article and it mentions shock level - quote: Add enough chlorine to bring FC up to shock level (or a little higher). BUT this article does not describe or give a link, to figure out what the shock level of chlorine (bleach in our case) would be for my pool. I know I'm aiming for between 3-5ppm on a daily basis. But what am I aiming for during a shock event? I added 31oz of bleach a few hours ago (to bring FC from .5 to 4ppm in my 4,240 gal. vinyl lined pool w/ SWG), as suggested by the "Pool Calculator". But my understanding is that that is a recommendation to get me to the 3-5ppm... is that also the Shock Level? Or is the shock level a LOT more chlorine than normal (as I've been thinking)? Thank in advance. ~ Doug