I got several zoa colonies on Friday and 2 of them are hardly open. There is no white cheesy funck on them and the poylps look fine, just not open. Any advice on whow to get them going? They are in a high flow area, have had a dip, and are under 175w of 20K MH lighting. Everything else in the tank is fine, including 4 other colonies that came in last Friday as well.