I hate the z&p game sometimes.... One day the happiest colony of purple hornets, that I grew from a single polyp to over 30, all closed up and never opened all the way again... I tried dips and everything. I am not sure if it's related, but when I notice my corals starting to look unhappy and all my params are in line, I just open the windows to my house and let everything air out. Seems to perk everything back up. They don't seem to have the issue during the times of the year when I have windows open anyways due to nice weather, but definitely when I don't get fresh air in my house due to the cold weather outside.... I see them occasionally irritated. Again... could it may have nothing to do with it, but it can't hurt to add it to the list of things to try. Good luck man.