I've been watching Nya lately... and I noticed something strange.
There was always a little patch of colour on her forehead that was a darker pink than the rest of her body, but lately it has grown to almost cover her whole forehead.
I've seen cases of septicemia on the head like this so I'm a little worried, and I wanted to get other people's opinion before I attempt to treat her.
Kyu, who lives on the other side of her tank seems to be alright. Despite being somewhat larger (as in fat, but not as in constipated fat either).
They're in a 6 gallon, divided tank with filter and heater. I normally do weekly water changes but because of work I wasn't able to do one last week, but I just did one now. I haven't put Nya back in the tank yet though.