I've had this zoa for about 6 months and got it with 9 polyps on it and it took off. But tonight I saw something on it I never noticed.
It's got a tube like structure on the bottle and bold black area on it with polyps growing around it. Is it bad for the colony?
Any idea what it could be?
It's got a tube like structure on the bottle and bold black area on it with polyps growing around it. Is it bad for the colony?
Any idea what it could be?

