How do I make the water in my pool match up to the pool calculator? Meaning I should have a 10500 gal pool. but when I add the bleach it never goes to were I was trying to get it. Let's say I want to go from 4fc to 7 fc. I end up more like 11 every time. Right now I play bleach dice. See what calculator says than go under. If is says to add 96 oz I may add 50oz. Sometime I'm right sometimes I'm wrong. It is getting costly to keep testing the water. I will prob have to order more reagents again soon. This will be my third time ordering if I can't get this under control.