Triggers are like any other fish, case by case, sdome worse than others. In nature they do eat inverts, therfor there is the possibility for them to do it in captivity, Also, please remember triggers are the "sand makers" of the natural sea. They will eat coral skeletons as well, so there is the possibility of him taking a liking to your SPS. Again, just worst case scenerio. I have a 6" pink tail trigger who is an absolute model citizen, she polices the tank and make sure everyone else is on their best behavior, Ive even seen her feed my suncoral. They have great personalities and are wonderful fish for sure, just keep your eye on it until get a good idea of its behavior.