Hi everyone, i have just acquired a pool and am trying to get an understanding of everything going on with it. The surface has been replastered fairly recently (about a year or so old) and has some staining going on. The stains are dull in color... grey/black. They are most visible in shade/indirect light, and they do not brush off with a nylon brush nor vacuum away. The water is really cold right now, but i tried to reach down as far as i could to rub against the plaster and it doesn't really feel slimy to me. The walls appear to have a more solid stain than the floor does. It looks to me as though someone tried rubbing something on the floor stains in some areas and cleaned it up some... but maybe that's just how the stain developed? I'd appreciate any input i can get on hopefully addressing this.
Here are two pictures on my flickr that hopefully show enough of what's going on... these were from before vacuuming but that didn't change the ugliness...
IMG_0799 by faid2black, on Flickr
IMG_0798 by faid2black, on Flickr
Thanks for any and all help!!!