Sounds like copper staining. Did you use any algaecides lately? Did you get the water tested for metals? At the pool store they mentioned acid wash...

Acid in the lemon?

Then perhaps a brushing with dilute muratic acid would do the trick.

I agree. A light acid wash should take care of those...

G'day Dave. Is your pool surface fibre glassed? If so, you just might have a cobalt leeching problem, meaning the pool may have to be drained and...

Thank you for this reply. What you say is really interesting as I do not add lawn chemicals at all, but do live in the middle of sugar cane fields....

Hi Bluelitening,

With regards to your problem, I suggest that you purchase a water stain kit. These are available from a variety of pool chemical...

what chemicals did you add?
sounds like there could be copper in the water

The green is copper from your old heater.

Any pool place should be able to test for metals. In addition, any water conditioner place should be able...

That sounds just like the jandy stain master that geeman suggested (which I actually did end up buying and using). Maybe I didn't describe this...

Hydrogen is probably not practical unless you have access to hydrogen gas. You just have to get the hydrogen to the stains. You could use vinyl...

I know spinach has a high iron content. Possibly seawead or whatever geese eat also has high iron. The stains look like iron

you can try to remove it with acid, this is how i have cleaned my liner many times.. i put muretic acid full strenght on the stain,it will dissolve...

When I was schoking my pool this year with chlorine, after an hours the bottom of the pool looked stained, a darker blu which was not removable with...

It is the high PH that has caused the stains. PH goes 8.2 and over then stains looking like dust will appear. I have salt system and fight same issue...

I opened and shocked my pool just a few days ago, as usual. Suddenly, a sand like substance appeared on the bottom and side walls of my pool. It...

Thank you so much for your reply.

I actually got phosphate free fertilizer..or I'd be in big trouble with algae by now. Luckily no algae...I forgot...

I have been told that Zyke stores in France supply a pad which will remove the stains

Thanks for the reply: White gunite, not sure what a marble finish is, so I think no. Yes I do use fertilizer, and yes some fertilizer may have gotten...

The good news is that you don't need to worry about your dumping a small amount of test reagents into your pool water. The bad news is that the fact...