Will apologize right from the start. I have limited info. This photo is from a coworkers tank. I have very little experience with tropicals. Here is what I know. 55 gallon tank. Added a Betta shortly after set up without cycling tank. Betta is still alive. Added two platties few weeks later one of which died other is still alive pictured here. Tank set up about 1.5 months now. I am concerned about the white spot on fin and the fact it is torn up. And the long white poop is obviously a concern. She does not have a test kit.so don’t know water parameters. I know missing info but can anyone help.



