I brought a three more Corys home to join up with the 2 I had already. They seemed to be doing great in the new tank, but this morning one of them had died. There seemed to be no signs leading up to this, or at least none that I could pick up on. The others still seem to be doing great, but as you can imagine I am pretty stressed out now. This is the first time I've lost a fish like this. I don't want to lose anymore, and I certainly don't want this to happen again. I also got an Albino Bristlenose (long fin) and I want to make sure he is doing well. Again, everything appears to be fine. Is there something I should do differently? Something I should keep an eye out for? I'm so upset right now, I feel terrible.