Hey everyone, this is my first post here and I’m in need of help I will put all the events that happened. I had an established tank that was running amazing. I bought a new Flower Horn and added him to the tank, after adding him he randomly died 3 days later not sure why just thought bad luck. Then about 3 days later my 7 Glass Barbs that I had for 3 months all died overnight when I was looking at them, I saw that they almost looked like their scales were flaking off and they had a white fuzz on them. Again, in my ignorance I thought just bad luck, I know I should have started doing more research, but I didn’t… yesterday 9-26 I bought another Flower Horn after waiting a week and doing a cleaning. After putting him in last night I woke up and checked on him and he was very lethargic and had the same white fuzz on him and he’s not looking like he’s going to make it. All the parameters are good on the tank. I have read it could be a fungal infection or a bacterial infection I’m just not sure what one would kill a fish overnight.