The kids love to play treasure hunt with a handful of pennies. I noticed today some pinkish spots here and there on the floor of the pool. I am wondering if they are from the pennies or some kind of algea. I remembered reading that copper affected/was a bad chem in the pool. The FC was pretty low today, I immediately added enough chlorine to bring the FC to 6 and will shock it tonight just to make sure but does anyone actually know what it is? I couldnt scrape the spots off or anything, they seem like a stain.