I had green algae over three weeks before finally getting it out (bleach to 15+fc 24hrs)....I have been trying to close my pool for 2 weeks since being green free but it won't clear....I used about 30oz 7% cheleated copper and numerous shocking products over the battle....CYA is 110 now (I diluted 1/2 and then read)...The pool has held over 5ppm fc and 0.5cc...Alk and CH is okay. Temps have majorily dropped (30's last night)....Really want to close asap but concerned about the stuff still in there (hazy, blue color)...Have backwashed numerous times and no chlorine losses...Even backwahed with MA per PS. Even put in a gallon of clarifier. Running pump 24/7. No hint of green (no chlorine loss either), but any ideas why pool won't clear? What should I do???? Sand Filter bad?