plaster surface discolored/fused with powder?

[mjberheide]

Spring 2012 I used a product called Green Out when opening the pool to help clear out algea. It required a high PH before adding the product so I used PH-Up a couple of pounds at a time till I got to the PH range. My water got very cloudy and when things cleared up I noticed my white pool plaster had various areas that had turned a dirty gray/brown kind of swirled pattern. When I tried to remove it nothing worked, it had fused with the plaster. I noticed when I sprinkled shock around that if the granules hit these areas before dissolving that these areas would turn black for awhile until the shock dissipated. Did not get this resolved in 2012, and this spring and summer the problem persists. It might be being compounded by DE media which seems to be getting past/through the DE filter. When sweeping the pool I stir up clouds of dust that has settled on the pool bottom. It's a 24,000 gallon gunnite/plaster pool that was resurfaced four years ago.
Looking for suggestions,
Mike

 

[Bama Rambler]

Welcome to TFP.

From your description it sounds like copper stains.
Do you know the ingredients of the green out?
I can't find anything on it. I can find clean to green but not green out.

You can try holding a vitamin C tablet on a spot for a while and see if it lightens it.

 

[mjberheide]

Don't know the ingredients in the "Green Out", maybe I'm not remembering the name correctly, I'll check with Leslie's (it might have been green to clean). Tried the vitamin C test when it first showed up and it was not copper. I've tried scrubbing with a wire brush and have also hit it with a powerwasher and does it not want to budge. Even tried acid inside an applicator with a built in scrub brush and that didn't work either.

 

[Bama Rambler]

Did the vitamin C take it off?

 

[mjberheide]

No, the vitamin C did not remove it.

 

[Bama Rambler]

How did you determine that it's not copper?
Vitamin C will usually remove iron but it won't always remove copper stains.

 

[mjberheide]

I was told by the Leslie's salesman and another pool supply person that it pretty much worked for all metals. My observations are telling me that the PH-up has somehow fused/got into the plaster and/or the leaking DE powder might have something to do with it as well. What do copper stains typically look like?

 

[Bama Rambler]

They're usually dark colored, but the big indicator is that they tend to turn black when in the presence of high chlorine levels.

 

[mjberheide]

The water was tested for copper and the levels weren't elevated when I first started having the problem, although by your description I think I'll have another test done. The sides of the pool have been dirty looking for awhile now and algea easily attaches to them as well as the bottom, so I've been sweeping and shocking alot.

 

[Melt In The Sun]

Can you post some pictures?

 

[mjberheide]

I did take some pictures and will see if I can post them. I do not have the camera with me at the moment, it will be tomorrow at the earliest. On another note, if I was to go with something other than a DE filter, do you have any recommendations?

 

[Butterfly]

The water was tested for copper and the levels weren't elevated when I first started having the problem, although by your description I think I'll have another test done. The sides of the pool have been dirty looking for awhile now and algea easily attaches to them as well as the bottom, so I've been sweeping and shocking alot.

Once metals attach as a stain, they are no longer in the water and not detectable with testing water for metals.

 

[Butterfly]

Could you post a full set of test results? You may have something else going on, too.

We need:

FC
CC
pH
TA
CH
CYA