The reason to use a QT!
Two weeks ago, I bought 50 Neon tetras from Petco ($1/ea). Within the first 48 hours, ten of them passed, but the other have colored up, are schooling, and eating like miniature pirannhas. There was even a mass spawning in the first week.
One of the larger Neons had its tail bitten off (probably by Serpae tetra in store tank), and I've been watching it grow back. Over two weeks, the tail went from nothing to about half sized.
Because I was watching this fish so closely, yesterday I noticed a small white fleck on its side. There was also one other fish with a white spec on its tail. I began treating for Ick. This morning I don't see any specs on fish, which means they probably are in the free swimming state, or it was just a random grain of sand or something else stuck to it. Hopefully I can nip this in the bud with ick meds and daily water changes.
Also just to be sure, I am using API General Cure to handle any unseen parasites. I realize I have no idea where these fish have been.