...right in the grout lines. It brushes off easily, even rubbing with my fingers gets it off. Wife just looks at me with a disgusting look as I brush it off saying, "it's just going to come back like it always has"!
I inherited this pool when I remarried. So, for three years she's been giving me the evil eye when I brush the waterline off. And she's right, it does come back within days. Since finding this site, I've learned so much. Now I just need to know what I'm dealing with here. Latest pool readings are from yesterday morning as I've not had a chance to test since then because I was putting salt in to get those numbers up and didn't get up before sun up.
Pool is clear as all get out. The black line does not continue on the wall of pebbletec, just the grout between the tiles along waterline and some of the tiles have just a little bit of black gunk extending from the grout onto them as well but for the most part, it's really concentrated on the grout.
What do I have here? Is this black algae?