Chromis acting weird

[the reef kid]

I have 6 blue/green chromis in my tank...All of them were eating well and acting totally normal yesterday, but today one of them is in the corner of the tank not moving a whole lot. He looks totally normal, other than a tiny little cut in his dorsal fin, though I doubt that has anything to do with it. He is apparently trying to eat, but is failing...it seems as though he lost all of his coordination. He'll bite at it, but miss every time. He is also very aggressive to all the other chromis that come near him. I'll get a pic if you want it...the water params are:
NO3-0
calc-425
pH-8.2
alk-10
haven't tested for mag lately...

 

[the reef kid]

Sort of an update: He can actually catch his food now, and he's been getting a little more adventurous, switching corners and wandering 6 or so inches from them. He's gotten less aggressive, and I've noticed he likes to hang out with my molly, who also likes to chill in the corner. I'm actually starting to think he's just stupid...

 

[Bifferwine]

Sorry I missed this thread. Chromis seem to go crazy once in a while. People have posted about it a couple times on here. I think you are right about the dorsal fin -- that likely has nothing to do with it.

I don't think chromis ship very well. They seem to have much higher death rates during shipping than other fish. Maybe a lot of their weird behavior are lingering effects from poor shipping. Maybe your chromis is just stupid after all? ;)