black/gray stain on fiberglass pool shell

[maggie31]

I have a new fiberglass pool. I am using pristineblue.
Ph 7.2
Alkalinity 50
Chlorine 0
After adding pristineblue ( copper ) pool got black,gray spots.
And a black stain on the waterline
Can somebody help me!

[jdlloyd1183]

Did/ are you using 2 ounces per 10,000 gallons of Pristine Clean to prevent the Blue from staining?? If not, get a 64 ounce bottle of it(49.99) and add the whole thing. This should lift the stain. It would be better to use POOLIFE Copper Stain Remover or Jack's Magic The Blue Stuff. These in my experinece with Pristine Blue stains seem to work the best out of all the things ive tried. The waterline is probably scale that has attracted dirt and oil to it, use Baquacil Surface Cleaner and a scub pad t remove it, or some sort of acid based cleaner to remove it. Also adjust your pool's pH to 6.8 to 7.0 during any stain treatment process. This makes the water more aggressive towards minerals and metals in contact with the water, aiding in stain removal. Keep me posted so I can continue to help you...