I do water changes 2wice a week on all 4 tanks.. I feed my all my fish once a day and it's homemade food... Also I test my tanks on a daily basis so I'm fully aware of any slightest change of any sort... I just hope this isn't something more then just a common mishap. I did also purchase some plants when I bought the silver dollar.. Not sure if that has anything to do with it.... And also how would it get into all 4 of my tanks?... And I also noticed something hanging out of my male jack dempsey, not sure if this is even related but maybe I could gain an answer... It's underneath him and it almost looks like 2 tiny fins hanging out.. And my male and female have been scratching off things in the tank.