Who Gives A Fish Forums

Yeah, and don't forget to check the temp consistency. If the heater's sketchy, it could be causing stress. What brand heater you using? I've had some crap ones fail on me before.

Dang, that's rough. I had a guppy do the same thing once, turned out it was just old age. How long have you had this little dude? Also, what kinda substrate you got in there?