New with question about cloudy water but balanced chemicals

Hi,

My dad has a 24' round above ground pool, that is about 10 years old. This season he opened it up and it was really green. After finding the poolsolutions website, we followed the steps and ended up with clear water for the most part. There was one small cloudy section that just wouldn't go away. Then after a couple of hot days all the water got lightly cloudy at the top half an very cloudy towards the bottom. I tried raising the chlorine levels again and it didn't get any better, same with back washing and letting the filter run for 24 hours. According to the water testing with the drops all the levels are right in the middle of the range they should be but it's still cloudy. We tried some clarifier and now my dad wants to get floc. It's been cloudy like this for almost two weeks now. Is floc the answer or is there something else we should be doing?