grape coral has a brownish streany thing comming out it's mouth. i have about 6 branches and 3 of them have it. the water flow picks it up and carries it around the fishtank. is my coral dying? i have never seen it before, it just started today.
My corals expel bits of brown stringy goo all the time and are very healthy. IMO nothing to worry about - food goes in, waste has to come out, and these guys only have one opening