hello all. i read the posts on brown looking dust that wont goaway which was determined to be some kind of brown algae. i have followed posts instructions and have added granular chlorine to shock levels (the test kit reads up to 5. when i test for chlorine levels i think there is so much chlirine that on the test kit the color of sample is almost orange) so i think that im keeping the chlorine level pretty high. ph is about 7.5.

pool is gunite,about 20k gallons. i added some de to sand filter and psi went from 7 to about 9. have pump going 24/7 since saturdaty night...every time i brush, brown stuff picks up right away and brushes off easy. but when i go brush again, the stuff is still there. pump has been on 24/7 so i would think stuff should be filtering out...ok, my question is,since those posts are from 2007 i believe, has anyone found a better solution that worked for them that dealing with these same problem? i wonder if i should use pure bleach instead of the granular calcium hypochlorite i;m using? these stuff just wont go away. water looks good,its that brown stuff that wont go away...can someone please advise.i wouldappreciate it. thanks in advance