My chlorine level has been so high I can't tell (it's been over 30ppm for the past week, with no CC, the guy at leslies confirmed). Once I got the PH level to 7.3 I kept adding bleach. Brush and vacuum daily, scratch my head in the morning. Same happened last year, but one day it just cleared up. I'm really hoping it's the sand. Another question: if the DE doesn't work and i decide to change the sand, how do I remove the top (I have a Hayward S240, i'm not sure if I unscrew the black cap on top, pry it off, or unbolt the rib around the middle)?