"Shock" is a verb -- something you do to your pool, not a product. When we say to shock the pool, we mean to super-chlorinate. You do NOT want to do that right now until you find out if you have metals in your well water.

When I say plain bleach, I mean plain, unscented laundry bleach. Clorox or better yet, generic from someplace like Wal-mart where it is cheaper. Most of us here on the forum use bleach as our source of chlorine.