We've had this same stuff since the pool was installed last year. I always thought it was dust and dirt. We had to dig out around the pool last year for code and now the grass is finally growing in, but I still get this dust the day after I vacuum. I thought maybe everyones' pool was like that. What can I say, I'm a newby. I still have a bottle of polyquat from last year. Do you think I should try that? I don't want to fade the liner. Right now I'm trying to get my CYA up since I had to drain this spring cuz of a hole. I always thought algae stuck on pool sides-that's what it does in my aquarium. Denise