Is it worse today?
Looks like a “burn”
Did a chunk of dried salt fall on it?
What fish do you have?
You can take a razor blade and cut off or around the “damaged” section.
I have one of these stars, it’s over 8 yeas old!
There’s a 3”-4” sand bed that also houses 2 to 6 engineer gobies (I don’t see them all at once, so I’m not sure how many are actually there)
I have never done anything to “clean” the sand bed
That said, I’m not sure why yours is missing that tip...
@finalphaze987
No need to purchase the (overpriced) male anthias
Get a group of females, the dominant will turn male
Good luck to the remaining members
May they live long and bring you happiness