I have a harlequin rasbora that is swishmg upside down. I think it is going to die soon. does anyone have a clue? Its in my quaranteen tank with 2 other rasboras and 2 golden wonder killifish. The three harlequin's have cotton mouth and I've been treating with almost daily water changes and salt, and it seems to have almost gone away. Does anyone have advice or ideas ?