I added a 25W heater a few weeks ago (you can see it in the last set of photos I posted) since it was getting cool in the office over the weekends. This morning I came into work to find the water was 40 degrees and full of dead and dying fish. It was fine when I left the lab at 2200h last night, so it must have stuck on sometime between then and 0900 today.
I didn't have my camera with me so I couldn't document the carnage, but I'll try to take a few photos over the weekend.
So far, losses seem to be 4 chili rasboras and most of my shrimp. Also, the HC seems to be cooked and didn't pearl at all this afternoon. Hopefully it bounces back but I don't have high hopes.