I apologize if I posted this in the wrong section. If I did, please move to the appropriate area. My tank has been up and running for about 6 months. I had some nice rock in the tank, then I picked a few extra rocks up about 2 months ago. Had some nice sponges, tiny brittle stars, and a tiny pencil urchin. Then I noticed this algae growing. It went from zero to about the size of my palm in two months. Looks kinda cool now.... Can anyone ID it for me, please? Good or bad?
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