I have these red spots all over my rocks. I'm guessing it is some sort of algae, but it is very flat and seems to form new spots more than expanding where it is. It doesn't seem to be a real problem, but my bristlenose plecos definitely don't eat it, and the few spots that have formed on the glass don't come off with the magnetic scrubber thing.
Anyone know what it is and if it is something I should be concerned about?
Anyone know what it is and if it is something I should be concerned about?