Wasn't sure where to post this, so here ya go. First off, I am 99.9999% sure what we have is NOT Algae .. I am meticulous about maintaining and testing our CL (and all) levels. We have a Polaris 280 Cleaner that I run at least 2 hours a day (Winter) and 4 hours a day (Summer). It does a great job at picking junk up & the pool looks GREAT. My other half noted the other day that he could wipe his fingers over the side wall (in the water) and there was some dark dirty stuff that came off. This was brand new surface (Fiberglass) 1 year ago. I am a little less diligent in my scrubbing of the walls with my large brush - so things probably accumulated over the last year. But I'm certain that this is just accumulated dirt giving it a dull-like look vs. pristine WHITE like when new last year.
So my question - what do YOU use to clean the walls and bottom of your pool? Does a simple WEEKLY (??) scrubbing with the brush REALLY maintain that? Do you hand-scrub it in the summer when you can get into the water? Do you dump some chemical treatment in from time to time to get it white again? (something Acidic?) What about a Magic Eraser (yea, tedious - but any danger?)
Thanks in advance.