Moment of silence....
Okay, I found a dead fish in my tank the other day. He hadn't been feeling well for a week or two (Hung around the bottom of tank. Didn't look like he was awful, but he wasn't too motivated to swim around), but I swung my pH too fast and the resulting stress seemed to finish him off.
I noticed a couple distinguishing features, but I'm not as proficient as I'd like to be with the fish side of my system. Mostly, I noticed some blood behind the eye. Does that mean anything?
Also, there was a blood spot under one side of the gills that I wasn't sure was supposed to be there or not.
Here are a couple of pictures: