I had a Bursa and a Niger (Both were small, about 2") in my 55 mixed reef for about 2 months until I found a buyer for them. They never bothered any corals on me (I kept them well fed with frozen and live ghost shrimp). However, I did lose 3 peppermint shrimp and 2 cleaner shrimp to them. So, you may be able to get away without them nipping at any softies, but your inverts will most likely be in serious danger.