Tank threads are about chronicling the trials and tribulations of a tank, so I suppose it's time to talk about the bad stuff. It is my belief that whenever the corals in a person's tank look really really good, the fish will start to cause problems (and visa versa). That is what has happened in my tank. I haven't lost a single fish in a year. The last fish I lost was my yellow assessor who got too stressed in the tank move, I think.
About a week after I got the kole tang, he came down with ich. I had ich in my tank once before, in my 29g. I quarantined all of the fish - both affected and unaffected - and they all died in quarantine and I had to rip apart my tank to catch them all. This isn't an option for me at this stage, so I decided to leave them in the tank try other treatments. I have been soaking the fish food in garlic for the past month and I have added a UV sterilizer to the tank. I've been allowing the tank to run a little on the warm side (83 degrees) but I don't want to let it get too warm or hypo because of the corals.
Thus far, I have lost the kole tang and one of my yellow clown gobies. The gobies were very stressed when I got them as they were subjected to a very long shipping time (box got left at the airport by accident) and were moved from tank to tank rapidly. He got ich almost immediately and disappeared. The other yellow clown goby I still have has NO signs of ich at all. (There was a third one that disappeared early on.) The kole tang finally died last night. He was looking awful and I considered euthanizing him two days ago.
As far as the other fish are concerned, some of the fish are totally unaffected. Both wrasses, my one blue-green chromis, one yellow clown goby and my firefish are fine - no spots at all. My tail spot blenny doesn't have any spots, but he's been rubbing up against things so I know he's got it. My lamarckii angel, spotted mandarin and royal gramma all have a lot of spots with the gramma being the worst and the angel being the best. All of the fish are still eating voraciously and swimming around. I am hoping that now that the tang is dead, the ich population will start to decrease because of a lack of a large, obviously suseptible host. Truthfully, I'm surprised any of my established fish caught it as I've had all of them for a LONG time and they aren't aggressive towards one another.