Just became owner of this pool approx 6 months ago, so unsure of the chemistry history. There are stains? that have been on the bottom ever since I've owned it -- I think that these are just cosmetic and am looking for verification. I'm also wondering what they are, and if it can be fixed.
I uploaded a (not very good) photo of the black stain, I think it might just be wear the pebbletec is worn down? Ignore the pool cage shadows.
I have photos of the white spots but its too large for upload -- the are three of them quarter sized in my spa.
I've tried brushing, does nothing. Haven't had a chance to look at them up close underwater.