Is there tissue still on the branches? If so it is still alive, I just got a seafan myself about a month ago and have been trying to figure out the right care for it. Mine was polyped out for the first week or so every day then I hadn't seen any polyps for the last two weeks and was wondering if it was doing OK or not.
Then I happened to come home from work about 9:00am one morning and it was extended. So I started watching on the weekend and what I discovered is it extends its polyps around sunrise and stays out for an hour or two after sunrise then closes up again.