I have seen mine do it often. Maybe a blue leg or something else was on it or a fish nipped it. No big deal. Blow it with a turkey blaster and if there are no little pieces blown off it, your o.k.
Yep, don't worry about it. Something could've brushed it, or it could be the start of a shedding period. Leather corals do this all the time. If the area turns dark/black, then you have something to worry about
awsome thanks for all the info. dont now what i would do with out this place.i have 2 seio 620 gph pumps and a quite one rated 780 with head presure about 580 is this to much flow for manly softs