Not sure what this is so I would appreciate someone oppinion. Is it good/bad? 90g Tank just up and running for 3 weeks. Rock it's growing on is fully cured from LFS Thanks
http://reefcentral.com/gallery/data/500/198749_MG_0443c.jpg
http://reefcentral.com/gallery/data/500/198749_MG_0443c.jpg