I’m fairly new to reef keeping and I’ve had my Fluval evo running for a few months now, with 2 Clownfish, 3 hermit Crabs and a Zoa frag. I started it with live sand and dry rock, and the filtration is only biological. There have been many different types of algae coming and going, but I’ve just noticed two areas of dark green algae that I’m not sure about. Could anyone identify this? And is it a problem, or should it be removed?