framerguy, dendrophyllia is genus, not a family. It does not include tubastrea or anything else. It's a pretty rare import. I belive you are confusing the genus dendrophyllia with the family dendrophyllidae. Dendrophyllidae does in fact include the genera Tubastrea, turbinaria, duncanopsammia, and dendrophyllia. I would think the hair algae is a major contributor of the closed polyps. My dendrophyllia are completely exposed to the light, and have a pretty strong flow one them. Most times you can still feed them even if they aren't completely open, but I know how it feels to have a sweet coral that isn't open when you want to look at it. Try to set a feeding schedule that you want and stick to it, eventually they will catch on. If your coral is in fact dendrophyllia and not tubastrea it will, when healthy, stay open the majority of the day.
