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

[newreefer_59]

Just started 2 days ago in my SPS/LPS 150 gallon tank. Have 16 fish, and none look good though they have improved marginally over the past 12 hours. Still cannot see 3 of my 4 tangs at all. I do have 4 mini maxi carpet anemones and they appear to be standing up. Is this a possible cause? Are they possibly mating or are they defending themselves? I did spot a bristle worm recently too. Anyway, any thoughts on this?

[daplatapus]

It would probably be good to give some background on your system. Size, how long's it been running,, actual test readings, any recent changes or additions, what you've done so far (e.g.. water changes, gfo, carbon etc.)
All those things might help pinpoint a cause.

[newreefer_59]

Has been running about 3 years, and give 20 gallon water changes weekly. Have not been home so another person has been caring for it, but says salt is fine and Nitrate is 0.1. But this morning, she says there is a "bad ocean fish smell".

[hfp75]

Check your skimmer and empty it
Check arround for leaks

[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.