Sorry about your loss. First of all, I would issue a subpoena for your (soon-to-be-ex? lol) girlfriend on how she introduced the nem while you were away? She didn't pour all the water that came with the nem into the tank, right? Like others suggested, I suspect she introduced something bad into the tank. If not already done so, run carbon to get rid of any remaining contaminants. Well, I run UV & carbon on my nem-dominant tank.
I have 3 ginormous (14-16") carpet nems in the tank -- trust me, I know that those guys can kill medium-large fish! Your nem isn't that big & sticky so unlikely the suspect. You can always take out the nem as process of elimination.
Good luck!
I have 3 ginormous (14-16") carpet nems in the tank -- trust me, I know that those guys can kill medium-large fish! Your nem isn't that big & sticky so unlikely the suspect. You can always take out the nem as process of elimination.
Good luck!