Please help

[mcarroll]

I have a brittle star fish. Could the star fish be a problem?

They are notorious for waiting in a cave for any critter to come in for a "peacful" night's sleep. I've had one eat a porcelain crab that was as big as he was! I've never seen anything more ridiculous. LOL They'll take anything they can get their arms around if they're hungry enough....and their arms are very effective.

Keep your eyes peeled. ;Wideyed

It still sounds like the purple could be your most likely suspect. But I wouldn't completely discount the serpent star or anyone else yet for that matter.

Chromis I didn't know could be a problem. He is the only one left out of the 3 I bought after tank cycled.

Like most "schooling" fish they usually focus their aggression on one another – that's most likely why you only have one left – they need enough aggression to survive in a school with hundreds or thousands of others like him. He might be the last chromis because he was the worst....so yes – another "likely suspect".

Clowns, Damsels and Chromis are all in the same family: Pomacentridae

To paint with a broad brush: clowns host in anemones, damsels and chromis host in corals heads, damsels are bigger. All can have a nasty disposition. The clowns are the most reliable in a tank since their hosting behavior seems to compress their territorial demands the most compared to their family-mates. The clowns we keep most are on the small side of the family too. Larger members of the clown branch of the family are known for being pretty nasty too.

So rearranging the rocks will be my first thing to do but what else should I do?

If there's any chance you think you could be feeding more – try doing that. Make only a small increase in the total amount of food foing into the tank – but maybe consider adding an auto-feeder that can drop flakes or pellets in the tank a few times while you're out of the house.

Starving (or not) will change lots of behaviors!!

 

[Tsev03]

I have been feeding more. I think my tank can handle it. I'll do more water changes too. I'm usually home so I can feed less more often and I'll look into a automatic feeder. Maybe I can catch the damsels and chromis in a trap. My clowns don't go near my nems ugh. But planning on putting them in their own tank if they start laying eggs. I'm not short on tanks lol. If I move all of those I can add more fish lol. I really want a female naoko fairy wrasse

 

[Tsev03]

So my wrasse is hurt again. I wonder if this giant crab I just found could be doing it. His pin hers r huge almost an inch long. Don't know how to get him out.

 

[mcarroll]

Yes, almost surely the culprit.

If that's his rock, remove him and the whole rock until you can get him out of the rock.

Trapping him could be very tricky as crabs can be pretty smart....but that's probably your next best bet....a loaded bottle trap would be my bet, but others might have better suggestions!