I have a 4 inch niger and a 4 inch bursa in my 125 with a bunch of shrooms ,zoo's and polyps and theres no problem at all with them chewing on corals . I can see where you would have a problem with stony corals . what with the color to atract them and then them actually being hard enough to ware down the teeth. but the softer ones are not going to give them the feeling they are after when trying to wear down there teeth so they would leave them alone .
:wildone: