u/7_romeo_7

I’ve had 5 panda cory’s in a 20gal (long) for roughly a year and a half now and never have I gotten problems with them.
However, recently I’ve been monitoring one specific Cory due to its behavior changing to a more shy and sick personality and it’s top fin looking shredded (video).
This morning I found a DIFFERENT Cory dead (video) I thought all others were fine but now I’m concerned more than ever.
The parameter readings are from right before this post
What went wrong?