can't keep a Yellow tang alive

[tamccain]

My boss has a saltwater tank. He is having trouble keeping Yellow Tangs alive. He is on his third right now and this one seems to be doing the same things the others have done. They hide in the back of the tank, stop eating and eventually die.

He seems to be feeding just fine. He feeds some freeze dried Krill. Some mysis shrimp, spinach and he has some algae sheets that he puts in for it to have some greens.

Tankmates are a few yellow tailed damsels, a domino damsel, a zebra striped damsel, and some other type of damsel, and one shrimp (not sure what kind).

All his parameters seem to be ok, and he has more than adequate filtration. The fish shows no other sign of sickness except what is mentioned above.

Do you have ANY ideas what could be wrong???

[Gilraen Took]

Not that I know a lot about salt, yet damsels are super nasty fish. They like to beat up on other fish a Lot. That may be why the fish is hiding at the back of the tank so much. If so it may just be starving because it doesn't get enough food. Other than that no ideas...

[Reefneck]

Either what Gilraen said or the damsels are picking on the fish and injuring it. I would not add any delicate fish like tangs without removing all the damsels!

[TheOldSalt]

Gotta concur; damsels & tangs don't mix very well. How big is this tank, anyway? That could also be part of the problem.

[Osiris]

That's what i was wondering as well, what size tank are we talking? And it's all damsel fish in there? that's just wrong.

[leveldrummer]

maybe be poor aclimation to the new tank too, once he puts the new one in, it gets shocked, and its down hill from there with the damsels on his back.

[Fishfirst]

also whats the turnover rate? Tangs need a higher O2 concentration than the damsels do so he may be feeling the lack of O2 before the damsels do. Also what do you mean by "adaquit filtration"? I need to see some readings pH, Ammonia, Nitrite, Nitrate? Did the tang have any abnormalities, such as a bulging stomach, white spots, red blotches, black spots, fading, ect.

[tamccain]

Here are some specifics about the aquarium. It is 38 gallon, PH 8.2, ammonia 0, Nitrite 0, Nitrate ~20ppm. He has a HOB filter that is rated for a 55gal tank. The tank looked perfectly healthy when bought and perfectly healthy for the first few days, until he started going to the back of the tank and hiding.

EDIT: The tank also has a powerhead to move more water and avoid dead spots. It also has silk aquarium plants, and NO live rock

[Fishfirst]

Well for one, yellow tangs need quite a bit more room than a 38 gallon, but that is something that didn't bring the demize of the tang that quickly. The Nitrates are a bit high, not enough to be the cause either. Sooooooo... it seems as though the damsels are the cause of the fish hiding and withering away. Another thing I thought of is the place you get your stock from might not be the best, and is getting/keeping unhealthy stock. However, if the damsels were attacking the tang or even displaying in an aggressive manner, this can stress the tang out to the point of death.

My advice: get rid of the damsels, there are plenty of hardy fish out there that are just as pretty (or prettier) and that don't have that attitude. Also, forget tangs, large angels, triggers, puffers, lions, squirrelfish, groupers, sweetlips, rays, sharks, eels, snappers, mandarin dragonets, and anything else that gets larger than 4 inches.

Look at fish like the following: grammas, dwarf angel, goby, firefish, clownfish (especially perculas), blenny, chromis, cardinalfish, and hawkfish.

Also check out my thread, "which fish/invert/coral to choose?"

[tamccain]

Thanks guys, I let my boss know that the damsel / Tang combination won't work due to the aggressiveness of the damsels. He was disappointed, but understood and he won't get another tang. I didn't tell him that his tank wasn't big enough, because telling him about the damsels was enough to keep him from getting another.