Molly lives but everything else dies
I have had the same molly for 3 years and she has made it through everything. She had 2 sets of children and they have since past. I have tried putting platys in with her but they all seem to die off right away. The water is fine I have tested it multiple times. So what is causing my fish to die off? Except the molly? I can't figure out why this is happening? Any suggestions?