My male Betta, I've had him for about a year and a half, just died. I came back after a trip 2 nights, and he was fine. then this morning he was dead. Water parameters are fine, Temp. at 76. He was in a 28 gal, heated, filtered show tank. All other tank mates (2 pepper corys, 1 Bronze Cory, 1 Pleco, and 7 neons) are fine.