ok one of my female mollies in swimming verticaly but not moving. she just goes vertical and stops moving. also her crap is red and the others in the tank is brown so there is already something wrong i just dont know what. please help me
Sounds like a bacterial infection, it can cause gas pockets in the intestine, or even effect the air bladder. It can also be age related, male mollies average 2 years but sometimes less, females a year longer, then things start going wrong until they die. You could try the antibiotic laced food (not anti-parasite) made by Junge, Maracyn-2, 0r Kanaplex.