man.. i hate seeing this kind of stuff happen to other fishkeepers.
same thing happened to me a while back when i brought home a wild caught wolf fish. killed the majority of my bichirs and they all started developing this weird whitish bacterial film out of nowhere yet the water was fine. I was able to save one of my bichirs by quarantining it and adding prazipro to his food and also used tea tree oil in the form of drops added to the water and increasing temperature.
same thing happened to me a while back when i brought home a wild caught wolf fish. killed the majority of my bichirs and they all started developing this weird whitish bacterial film out of nowhere yet the water was fine. I was able to save one of my bichirs by quarantining it and adding prazipro to his food and also used tea tree oil in the form of drops added to the water and increasing temperature.