It began to open the instant i added it to my tank, so I would assume if it were a health issue the coral would not open at all? it has been in my tank about 30 hours now. Could it be that the green parts are just so short its hard to see them right now, and will eventualy grow? This is my second encounter with GSP, the first one I got was a frag, but I always remembered it having visable green.