<a href=showthread.php?s=&postid=13315096#post13315096 target=_blank>Originally posted</a> by ccampo
Long time with no updates Wachuko, your tank looks great.
Now, that star looks like an asterina star, just a little bit darker than normal, and if that's the case they're harmless, consider them as part of your cleaning crew, but be careful with them 'cause they procreate like crazy, they can be easily removed from the tank if desired, when attached to the glass.
Maybe someone else can identify it in case it is not an asterina star.