A sad update--the loopy panda cory died yesterday. It may or may not have been related to his problem--he was the last (I hope) of four sudden panda cory deaths.
One day I found two dead, and I suspected that something had attacked them, because they were missing parts of tails and pectoral fins. A couple of days later one of the cories looked a little whiter than normal, hours later I noticed his tail looked a little frayed, and then the next morning I found him dead. A week later, another one showed a frayed tail, and I thought, oh no! But that one continues to seem okay otherwise a week later. Then the loopy one got a frayed tail and he died pretty soon after that. I've been keeping an eye on water params, and they're all normal--nitrates vary from near 0 after a water change to 20
ppm when I do a water change (this would be my "normal" once-a-week 25% water change, though I sometimes do twice-a-week 30-40% water changes that keep nitrates down near 0). None of the cories showed any other symptoms that I could note, and I tend to keep a pretty close eye on them (especially after the first two deaths).
Do panda cories need cleaner water than 20
ppm nitrates?
I've also seen people say that pandas don't do well above 77 degrees F. What happens then? My heater is set to 76, and is "guaranteed" to be accurate within a degree, but the stick-on thermometer on the outside says 79, with no accuracy guarantee.
On the other hand, maybe I just got a bad batch of panda cories....
The first two mysterious panda deaths occurred within a week after I introduced a bristlenose pleco and two pearl gouramis to the tank. I didn't notice any ammonia/nitrite spikes, and I was testing the water daily after they came in. I did not
QT them, but if I had I would have put them in the tank two weeks later--they have seemed otherwise healthy, as have the swordtails.
I waited a week after the first three deaths and then got three more panda cories--the remaining ones were seeming a bit down in the dumps. Everything has seemed okay with the new ones and the one remaining unaffected old one.
Shoot, I probably should have just started a new topic. I just wanted to update the status of the loopy panda cory, and I wasn't thinking I'd get into all this detail (I would have posted earlier about the panda cory deaths, but I was short on time).