try to increase the flow towards ur sunnine.. during feeding time they will open up nice nice.. as for the dead part might be during the time u got it the tissue is already semi dead.. as long as got new polys come out its a small issue liao le..
no pic.. pic can be found on resun web site sorry about that..
as for in sump or out sump its ur choice.. just make the tube longer thats all.. for me i'm using in sump