Fish all look sickly, yet water seems fine...HELP!

[daplatapus]

How long has this person been looking after the tank? Is there a possibility she's been topping up with salt water instead of fresh? Obviously diagnosing this will be more difficult if the person on hand hasn't much knowledge on testing, proper water parameters etc. Is there anyone else (a reefer) you know in Okotoks that can pop by and check?

[newreefer_59]

And things have been good as I have made regular checks to ensure all is well. I wonder if a tang or two has died and is in the live rock somewhere. I am headed out this eve, but wantied to get some thoughts.

[hfp75]

2 days and a dead fish should be gone if you got a CUC. Sometime I just toss in a silverside for them to munch on....

Mines a 55g Main & 10g sump

[daniella3d]

maybe one fish died and caused ammonia, and that can burn the remaining fish or create a lack of oxygen. 16 fish in 150 gallons is a lot, unless they are all small fish. It's 5 gallons of water per 1'' of fish, so that's 30'' of fish, devided by 16, all your fish would need to be like 1.8'' and I am guessing they are much larger then this....

Just overstocked I guess. I don't know the size of your sump but that still make it a lot of fish. Even in 200 gallons your fish would need to be 2.5'' each.

[newreefer_59]

I think that may explain the sickly looking fish.

[asylumdown]

Well, the first question should be what killed the tang? I'm sure a rotting fish in the water didn't help if it was a decently sized animal, but fish don't just die for no reason. Unless you've had this tank for years and years, chances are good it wasn't old age. If something stressed that guy out mortally there's a good chance others are being subjected to the same pressure.

[newreefer_59]

but we just saw another one today. looks to be around finger width and 5" long, so was not as large as the firsy one, but is still pretty big. Would that have been a cause and should I try to remove it?

[naesco]

Originally Posted by asylumdown

Well, the first question should be what killed the tang? I'm sure a rotting fish in the water didn't help if it was a decently sized animal, but fish don't just die for no reason. Unless you've had this tank for years and years, chances are good it wasn't old age. If something stressed that guy out mortally there's a good chance others are being subjected to the same pressure.

What asylumdown said but:

Both a powder blue tang and an A.nigricans (looks like a powder brown tang but has no orange on it) will die for no apparent reason most often taking a few of their tankmates with them.