Just got home today and saw one of my damsel fish and there's something up with his eye. Here are the best pictures I could get:
Specific Gravity: 1.023 (a little lower than the 1.025 I try to keep it at but still within range, I believe?)
Nitrate: 20 ppm
, maybe a little bit above, couldn't be more than 30 ppm
I did a water change this weekend, part of the 10% bi-weekly PWC
schedule I use. The last time I distinctly remember seeing this fish looking normally was last night, there were no problems at all then. Right now, the only thing out of the ordinary is the eye, there is no aggression beyond what is normal, and he's behaving the same as he always does.
Here's a page with an updated description of the tank and all of its specs:
Tank Specs | Adam's Flog
In case it's relevant, the tank was moved about 4.5 months ago with no casualties. I didn't see any traces of a mini-cycle or anything. This particular fish was one of five that survived my previous tank crash. That was about two years ago, and during that process he was undoubtedly exposed to whatever caused the tank to crash (I still don't know what it is) as well as being exposed to the ammonia/nitrite that happened when he was moved to a QT for a couple of months while I started from scratch.
Finally, the only other disease-related thing that's ever happened in this tank is detailed in this thread:
Something on Bangai Cardinal's lip
I've had tons of success with this tank and I think I've listed everything that could possibly be relevant here. What could be wrong with this guy? It may get interesting if I have to QT him, I don't know if I could catch him without tearing the whole tank apart, and even then I have two tangs I'm QTing right now (making sure they don't have ich before I put them in the tank).
Thanks for your help.