I purchased a sun coral at the Nashville swap 10 days ago. I placed it in the tank and for 2 days didnt see anything. Then we saw a couple tentacles peeking. I tried enticing with food and nothing.. It did that a couple days in a row and since then it will not open at all. 3 days ago I moved it to a different area of the tank to try a new location and its closed tighter than ever.. My wife thinks it may be dead.. How could I tell if it is dead for sure? What should I try to entice it to eat? I am thinking of covering the coral with a bottle cut in half and trying to feed.. I have frozen brine shrimp, frozen mysis a couple different other frozen foods that are supposed to be great mixes.. Is my problem the frozen food? should I try something different than those? Any advice is greatly appreciated..