This year I have been dealing with a very fine dust that has invaded my pool. It gathers on the creases in the liner, corners, depressions, etc. I can brush but it reappears after a day or two. Vacuuming helps but it comes back a few days later. The pic makes it look black but it is actually brown (not chocolate brown but weak coffee brown). My numbers are perfect and and for the most part always have been. The pool is 3 years old and has been SWG and BBB since it's birth. I battled mustard algae once but have no cc's or OCL.
I sealed my stone coping (Arkansas Flag) at the start of the first year. I have not sealed it since. I also did not have this issue until this year. I am assuming I am seeing very fine dust being eaten off the stone by the salt. Some of the stones do look like they have some surface deterioration.
I recently added two coats of sealer and hope I am not too late.
I really don't have a question. I was just throwing this out there for informational purposes. Any comments would be appreciated though. Especially if you have dealt with this same issue in your own pool.