I think I'd have ripped it all out days ago. I had AS in my tank and after two years, I had to supplement with ferts to get healthy growth. So I think you're putting up with a lot of grief for not much benefit.
I also had a new unused bag of AS do that. After two weeks of near constant water changes and little change in murkiness, it all went to the compost pile in the back yard.
As you can probably tell, I'm not an AS fanboy.