I filled my new pool from the well and after adding chlorine lots of red stuff accumulated on the bottom of the pool. Today I vacuumed it all up. After I was done I found red scum on all the white surfaces in the skimmer. I rubbed it with my hands and it was almost greasy. It just kind of smeared around but wouldn't come off.
What is it and how can I clean it off before it stains?
What is it and how can I clean it off before it stains?