Dark spot around tiles - photo included

[Aquatica]

Hi,

Anyone have any idea what the dark spot is around the tiles? I tried resting a chlorine tab on it over night and its not organic. Tried brushing with a steel brush but its still there.

Any clues?

Thanks!

 

[PSW]

I am not exactly sure which part of the picture I should be looking at. Are you talking about the dark strip above the tile line (kinda looks like a shadow)?

Have you tried testing it for a metal stain? Crush up vitamin C tablets and put them in a sock. Hold the sock against the stain for 1-2 min and see if that lightens is at all.

 

[Aquatica]

I am not exactly sure which part of the picture I should be looking at. Are you talking about the dark strip above the tile line (kinda looks like a shadow)?

Have you tried testing it for a metal stain? Crush up vitamin C tablets and put them in a sock. Hold the sock against the stain for 1-2 min and see if that lightens is at all.

Hi Blake, yes right above the tile line. I have some ph decreaser granulars I can try. If its a stain then we need acid. Client might be able to live with it for now. If it is metal stain then could only be coming from below the diamond brite. It's impossible to get the right Vit C on this island. I've tried before.