The LFS staff said that they were just star polyps; I figured they were GSP, because when I turn the lunar light on, the star polyps turned bright green. I am new to this so who knows. I took the Xenia off the rock and moved it; I think the Blue Leg Hermits might have played a role as well, because they were always gathered around the live rock the Xenia was attached to. They might eat algae and keep the tank clean, but they are pain in the asses.