Ok so this tank is giving me trouble all of a sudden. No idea what's up. Added a third guppy on Sunday. The lfs it came from has very healthy tanks. Bought from them many times before always been satisfied. Guppy was healthy when we got it, healthy the next morning, and dead when we got home in the afternoon. So I thought maybe it was bad luck. But today another guppy was looking sick, a few hours later and its nearly dead.
Let me try to give some more specific info:
The tank has been running fine all summer. Plants growing, cycle definitely complete. It gets regular water changes. The panda cories have been healthy the whole time, and still are showing no signs of distress. No lethargy, no rapid respiration, not swimming funny, still eating well. I'm just totally stumped as to why the guppies go from healthy to dead so fast. The second guppy was healthy and eating, and then dead about 12 hours later. External signs are minimal: slight loss of color, trouble swimming (one guppy lost use of its right fin, and was also unable to swim down from the surface), as far as I can tell there is no visible rot or fungus, and poop seems normal.
I'll post water parameters tonight, I really want to get this figured out