It happens lol. Colony to the left of the pic got knocked off by my hippo a while back. Once it gets to a point it is bound to happen. The colony only had about 3/8" holding it onto the rock. I fragged it up, gave most away, put some back and just last week it happened again lol. Seems it is in the way of where the hippo wants to swim lol.
I’m ready to get rid of my Hippo tang. He’s way to obnoxious. Beautiful fish, but I’d say reef safe with CAUTION. He’s fragged my whole tank.