Hi guys, tanks has 8 month roughly, started few months ago to get coralline algae growth and since a month or two i've noticed that some patch of coralline are gettin outgrown by this darker kind of "don't know what is it". Is hard, can't really scrape it off unless i really apply to it, turkey baster does not do anything, can't say precisely the color since i'm color blind but it's much darker, would say reddish or brownish, surely you can say it better.
Any idea on what is it? normal?
Any idea on what is it? normal?