My Ex is away for a month and has left me in sole charge of her two main fish tanks. I have a book of to do's with all the paraphernalia for there wellbeing. The water is crystal clear and all pumps and aerators are working. I have been feeding them mainly with blood worms and pellets. I have been changing 20% of the water and replacing the top filters regularly. But yesterday One of her best fish a big chap about 8' long was dead in the bottom of the tank . Any ideas please. My only thought is have I been giving them enough blood worms, she did emphasize before she left not to overfeed them. Have I been giving them enough food, can large fish starve to death. I have upped their food now just incase. Any help or ideas would be appreciated.