If you really have a CC of 6.6 (and it sounds like you do ) then at least you know the chlorine you're adding is fighting the stuff in the water. So...Watermom and Mbar have laid out your best plan--get that chlorine back up to at least 15 ppm and hold it there as consistently as you can. Brush the pool every day, keep the filter running and backwash/clean as the pressure indicates, and it will clear up. You are going to need a good dose of POPP--pool owner patience and persistence--the pool took a long time to get into its current condition, so the solution won't be overnight--but the solution WILL work if you apply it.

Janet