Quote Originally Posted by Watermom View Post
Carl may have not read the entire thread. Shock level is what you want. Even though there is no algae, you have huge chlorine demand. So, you do want to shock the pool and keep it at shock level until you get past it. Sorry for the seemingly conflicting advice.
That would be true....oops. But if you're losing 10ppm overnight, it may well be some other contamination you have to metabolize. Algae is, in an of itself, harmless. But it "bleeds" the chlorine out of your water so it can't metabolize the really bad stuff, like animal, avian and human fecal matter, and other bacterial contamination. Algae's just the most obvious and visible.