green hair and 0 copper onwater test

[tltmom]

From reading a lot of posts here on TFP, I see that green hair from swimming is caused by excess copper in the pool water. Only the blondest member of my family got a slight green tint to her hair, which fortunately came right out witha "malibu" treatment at a salon.
I had the water tested at the pool store, which showed a copper level of 0.
The only 2 places I can think of that we could have gotten copper from are the heater and the use of algaecide. I haven't used any algaecide this year, but I used some last season (in my pre TFP days), and my PB closed the pool last fall and used some then as well. I'm not sure what algaecides were used, so I can't be sure if they contained copper or not. Probably a total of 3-4 quarts have been added to my 30,000 gal pool in total.

In regards to the heater, I don't think the pH has ever been below 7.4. It's a constant battle to get the pH down, so I don'tthink a low pH could have corroded the heating element. But I did accidentally over dose the pool on salt this spring (=4600ppm) which I've gotten down to 3800-4000. Could the high salt level have corroded the heater? It seems to be working fine.


I could try taking a sample to the other pool store in my area to see if they can find copper in the water, but I'm sure it must be there, since we are seeing some green hair. My daughter has swum in other pools this summer, so I suppose the green hair could be from another pool, but she has done most of her swimming at home

Just curious what the experts thought, if my limited use of algaecide or the heater could be the source of copper in the water.

 

[JasonLion]

Salt would have to be quite a bit higher than that to pose a problem for the heater.

Green hair is invariably copper. Copper tests are not completely reliable, especially at lower copper levels.

The algaecide is a possibility. That would be enough to affect hair if it was a copper based algaecide.

 

[tltmom]

Thanks for the reply.
I will try to post a few pics of the plaster. It's only 2 years old, but there is some fairly severe grey ?staining/mottling.
Worst in deep end, a little scattered randomly in the shallow end. Stains are smooth to touch, have been steadily getting worse, were visible from the beginning of last season. It's a long story, but proper plaster startup was not done.
I don't like the appearance of the plaster, but I can live with it. I definitely don't feel good about the green hair! My daughter is not a fan.

first pic is shallow end, 2nd is deep.

My questions are
#1 any thoughts as to whether this is mottling/hydration vs. copper staining (or both)?
#2, how do I go about determining what sequestrant to use & how much?
#3 Also, any possible bad side effects to look out for when using one?[attachment=0:3aeax1qm]photopoolstain#2.JPG[/attachment:3aeax1qm]