Missing Convict

Ok. So some of you who have read some of my previous posts know that a couple of weeks ago or so, I upgraded to a larger tank.

Since then, I have added 2 fish. one of them a Diamond Goby, the other is a small Convict Tang (about the size of my Coral Beauty).

Yesterday, the Convict disappeared. I searched a bit for him but no luck. Figured I'd give him till today to turn up in case he was hiding. Still today, I cannot find him at all. I even moved some of the rock and used the baster to blow some of the sand around. I have looked to the best of my ability with a flashlight in every crevice at every angle. Still no luck. Even though I have a lid on my (internal) overflow box, I check there, in the sump, sock, and behind the tank. I have a cabinet style canopy so he couldn't have jumped out anywhere else.

Previously, he was fine. No indication whatsoever that anything was wrong. Very happily swam around with my Clown and Coral Beauty as if they were in their own little group. He had eaten fine and when not fed, picked at the algae around the tank. No abrupt moves or swimming fast. Just normal as my other fish do.

My question is:

Do I tear all my rock apart? It took me 3 separate sessions to build, for 3 hours each. It would be a LOT of work to tear it all down.

Do I leave him for the cleanup crew? And if so, will my parameters spike?

What could have caused him to die?? Is it possible that he is still alive and hiding?

I have checked the params every day since I moved everything to this tank and all of the parameters have been and still are completely stable. 0 nitrates, 0 nitrites, 0 ammonia, 8.2 PH and 1.024 salinity. Temperature ranges at the MOST from 79-81 max.

I am running a Mag 9.5 pump with a Bubble Magus NAC6 skimmer, a carbon reactor, and Chemi-pure Elite in my sock. There is a substantial amount of LR and even more in my 30 gallon sump. Also a Hydor 1150 gph powerhead and I am still dosing MB7 every day (3 capfuls).

For CUC, I have a cucumber, 7 hermit crabs, 9 nassarius, 6 turbo snails, 1 emerald crab, 1 blood shrimp, 1 peppermint shrimp.

(sorry for the crappy pics. they were taken with my cell phone. I included them so that you can see the rock layout)

It seems very sudden. And all other fish and coral are doing better than fine.

 

The tank looks really beautiful.

I would not start moving rocks.

If you find the fish and it's dead, not much you can do about that. If it's alive you will proceed to stress it out big time. The only good intervention is a wait and see at this point in my opinion.

That is a lot of cured rock I would not worry too much about a decline in water quality.

 

Thanks COrailline! I have no idea how many lbs that is. Any guesses?

Also, it just occurred to me that since the Convict, I have added a rainbow bubble tip Anenome. Is it possible this could be the culprit?!

 

Could be a culprit, not the most likely though.

There is no easy answer why fish suddenly die while looking otherwise healthy and in a tank with decent water quality.

All you can do is feed a good diet, watch for disease and aggression, keep water quality stable.

Honestly I am still amazed that we can keep boxes of saltwater successfully.

 

Small convicts can be very difficult to keep. Likely it was stressed and just didn't make it.