Normally when a fish dies, it's upsetting but not really that bad. However, my betta girl had so much personality and was just an amazing fit for my tank! I don't know what happened, she was fine until after I did my big 60% water change and rearranged the decor. Could that have stressed her enough to die? She was acting odd and swimming at the top of the tank yesterday and just overall lethargic. Before this, she was having problems with being bloated all the time. She was such a piggy and hogged all the food to the point that she would get her stomach all distended and lumpy. I fasted the whole tank for two days, and that helped, but of course she went back to being bloated immediately (the fast ended the day after the big tank re-do). All of my other fish are fine and active. Any ideas what could have killed her?