cardinal sucking air...

[mandarine65]

... .... from the top of the tank. I checked the sg and it's at 1.021 and all other parameters are right on. I just got him on Sunday and he seemed to have acclimated well. My fish book tells me this behavior can be from poisoning or the salinity could be off. Any ideas and how can I help him?
(posted this in the disease/treatment boards, but I thought I'd try it here too).

 

[globaldesigns]

is he eating? is he just sitting in one spot, or swimming?
Can you post your parameters?

 

[mandarine65]

Nitrate 20
Nitrite between 0 and 0.5
pH 7.2
Alkalinity 180
He was just staying in one spot. But when I went out just now to test the water (I had checked it this afternoon, but didn't write it down) he wasn't in that spot. I had turned out the lights after I posted and everyone in the tank had gone to sleep.
When I fed them this afternoon I did notice that he seemed totally disinterested in the brine shrimp and I didn't see him eat anything.

 

[culp]

my Sailfin Tang does some thing that sounds just like that every couple of hours. have no idea why. but i have had him for about 6 months and is doing just fine.