[Dara]

I have 2 emerald crabs in my tank and neither of them have ever touched my corals. They pick at the rock all day and demolish any type of algae. Green star polyps are very hardy; mine survived having a plugged in strip light dropped into the QT with it, a few days with no light until the strip light was replaced, being knocked off it's rock by a turbo snail, and being covered with sand by a diamond goby who is determined to erect a sand castle skyscraper in my reef tank. In spite of everything it keeps growing and spreading. They love iodine, you might want to add it to your tank regularly. All the soft corals and polyps spread faster with it in the tank. Good luck with your star polyps.