Well, ive been petsitting dogs cats and fish for my moms friend for money. I just got back from their house, and one of the fish was dead. It had its belly blown open with an organ hanging out of it. Ive been worried I was overfeeding them for awhile, so I think thats the problem. Also the fish are small koi and minnow sized fish that is white and has black stripes on it. I odnt tihnk they were striped bass. So what am i doing wrong? Thanks.