Black and White Stains?

[abrink]

Hi All,

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.

Thoughts?

 

[Melt In The Sun]

Hard to say. I think it's more likely to be black algae than worn pebble. It's warm enough to swim in Florida, right? Hop in there and see if the black streak is a bunch of little fuzzy green-black bumps.

 

[JasonLion]

Do you us any copper or sliver based algaecides?

 

[abrink]

I never have, but hard to know what's been done in the last 9 years. I don't think it's algae, FC is 6.5 and CC is 0.
Do you think it's a metal stain? Anything that can be done?

 

[JasonLion]

If it is algae it will brush off, or at the very least some of it will brush off. It looks more like metal staining to me, but it is always difficult to tell from photos. If it is metal staining, black stains are some of the most difficult to remove.