How long do I continue keeping the chlorine at shock level? A little background: I bought a house with an AG pool, 13,000 gallon, green, nasty with living creatures. I got rid of the creatures and the green, the levels are all good but the pool is still cloudy. We just changed the sand in my sand filter just last night because we didn't know how long since it'd been last changed and we found a bag of 'kiddie sand' near the filter so I assumed that was what she put in it. Maybe that will do it? I've let the chlorine go back down to the '3' level right now because all of the green is gone, the stuff is cleared from the bottom (got in this last weekend and felt around for the last of the pine needles) and all else seems good.

Thanks!