I need some of the experts here to help me identify these orange spots appearing in my pool. They are forming on the water line tiles and on the pool walls - there don't appear to be any on the pool floor that I can tell. The ones on the tiles wipe right off, but I have to brush the ones on the walls pretty good to get them to go away. Any ideas of a) what these are and b) how to get rid of them. PH is at 7.6. I will have to get the other test results and post them later.