Well, I was hoping that the travel stress had just gotten to my three new neons, which all died (1 the day after I got them, 1 the day after that, and 1 the day after that, yesterday). But I woke up this morning to find one of the original neons dying as well. (for story on the first three, see
this)
I did a 40% water change in hopes of diluting whatever is apparently in the tank now. Water parameters pre-change were the same as they were yesterday: pH=8.2, ammonia=0, NO2=0, NO3=10.
I saw this fish as it died, and it was twisting in the air: basically doing an aquatic version of the corkscrew. None of the fish lost color or had any marks on their bodies, and they stayed in the main area of the tank for the most part (not hanging out by the surface, heater, filter, or bubbles. I have no idea what's going on :-/
Any ideas? I (and my 2 remaining neons) need your help!