Originally Posted by Ami
Any ideas on how to tell if the neons are healthy (other than looking for nipped fins?)
I lost 5 platys in my 20 gallon before and during my trip. They got a BAD case of Ick and although we used Ich-attack (recommended by our LFS). They said that the fish get ick if they are stressed out and there is no way to prevent it...is this true?
Yes, that has been my experience. I am one of several aquarists who believes ich is always present; there is no other explanation for the fact that it can break out in an established tank to which absolutely nothing new has been added for months. Stress causes ich because it (stress) weakens the fish's immune system. Stress from all sorts of things can occur.
Healthy-looking fish is not easy to describe. Basically, it means the fish is behaving as the species should, has reasonably good colour (remembering that in bare store tanks many fish will be washed out and this is stress but not indicative of poor health necessarily), no clamped fins, no shimmying movement, etc. And obvious no spots, tears, lesions on the fish's skin [torn fins are not always a problem, this can happen from many things, including past nipping]. I always stand for many minutes in front of the tank, motionless, to see how the fish are interacting. Knowing the species helps, so you know what to look for in this regard. Male displays among characins, frisky play, sparring between rival males, etc. I think much of this comes with experience.
I want to get hold of a group of Black Ruby Barb, a beautiful Cyprinids and very well suited for my 90g river habitat. I found some at a local store from which i frequently buy fish. But there were 3 dead fish floating in the tank, and 2 of the live fish had very red gills. Sure signs of trouble, even though all the other 2 dozen looked bright and lively. I left them, reluctantly; I though maybe I could quarantine and treat them...but decided best to wait. Well, a week later, there were only half a dozen swimming fish, and a couple floaters. The staff fellow said most of them had died suddenly. Obviously they had some sort of pathogen, and without knowing exactly what, treatment would have been impossible and I would have wasted my money.