I have a 25 Gallon tank with 6 different fish. 1 medium goldfish, 1 female sword tail, and a mixture of platy's. Out of the mixture of platy that I do own I only have one male. All of my other male fish have died. I know that my only remaining male can be a bully sometimes, but whenever I buy more males they always end up dead. Is there a reason why to this? I think that both the males and females have a different life span, unless I'm wrong and he is picking on the other males until they die. Any hints, or ideas as to why they keep dying?