Hello everyone, this morning my pet Glow Betta passed away and im not exactly sure why. He was a very healthy fish, and from what I could tell he was happy. Always excited by food, always did well after water changes. I took very good care of him. Its a 1.5 gallon tank but he had a filter and a heater. Plus decor and a little hammock he loved. Luckily he's an electric green glow betta so he's relatively see through. I attached a picture of how I found him this morning. He was alive and healthy enough last night. I just want to know if anyone knows what happened to him and how to prevent it from happening again. Thanks for your time.