Hey everybody, 2 of my large silver arowanas died this week and I dont know why. They both were about 15 inches and doing fine (no fighting, they got along well and ate). I had three in a 125 gallon with a fluval fx5 and the tank is well oxiganted and clean. They both died a few days apart and were floating vertical face down. All I can think is that I fed them some feeder comets, maybe they had diseases, would that kill them that quickly?