Okay here I am again. For the past 2 days I've been monitoring and shocking my pool to get it clear. As posted in my previous post one pool store said I had a CYA of 100 while the other store said my CYA was 40 (both water samples were taken at the same time and were tested within 20 minutes of each other). I decided to use the higher reading in order to determine how much bleach to add to shock. I shocked beginning on Wednesday night, Chl level was still at 25ppm the following morning and did not show a drop until mid to late afternoon, added enough to raise level to 25ppm again last night, reading this morning and at 2pm today remained at 25ppm. Reading now is approx 16ppm. Will add more to raise to 25ppm again and hopefully water will continue to clear....it does look clearer-I think! Will have my water tested at the pool store tomorrow to get a new CYA reading. It seems my chlorine level isn't dropping very quickly since it doesn't drop over night....it's taking approx 18 to 20 hrs to show a drop. Is that significant? Do I keep shocking until water becomes crystal clear?