I have 1 female motoro and 2 male motoros in a 500 gallon tank. In the past 2 weeks the 2 males have been beating up the female. She has bite marks on her. Nips around her and it looks red on one of the spots on her. They are all around 13''. I have a 45 gallon hospital tank but I am not sure if thats big enough. Why are the 2 males al a sudden picking on the female? what should I do?