I have a Coleman AGP 16'x4' that ended up green before we could use it. I followed the directions here and got rid of the green, however I haven't ever been able to get rid of the cloudy water. I was previously using the cartridge filter that came with the pool but decided to upgrade to an Intex Sand Filter ( I believe 2,800 GPH) thinking maybe it wasn't powerful enough to clear everything. I have been adding chlorine to shock levels daily as I thought maybe the algae wasn't all dead. The FC doesn't seem to drop overnight, although with my OTO kit I can't measure above 5, so I guess I wouldn't know, however the sunlight during the day kills it. My CYA still reads zero on the crappy 6-way test kit I have. I tried adding CYA through a sock (I don't have a skimmer... yet...) and after over a week in the pool it never really dissolved, just let out crystals every time it was bumped or the water jet hit it.
I have had the sand pump installed now for three days running continuously. My pressure hasn't risen since I turned it on. It has great suction and flow so I know it is circulating the water well. I tried clarifier (and was careful to use only the necessary amount) with zero change. I honestly have no idea what to try next, but I know it is getting more and more tempting to just drain it and start over, although that would be awful. Any help is greatly appreciated!