Did you do the DE test on your filter?

High chlorine will help clear your pool, if there is still live algae. But if it's all dead, and simply being forced through your filter by the typical above-ground 'over-sized pump / under-sized filter' combo -- chlorine won't help clear the pool. (You STILL must maintain chlorine, to avoid growing a NEW crop of algae!)

Do the DE test. (#6 above)