In the past 24 hours, all of my fish have died, except for one otto cat. I am going to do a large (50%) water change, and I am going to remove the glo-rock I put in the day before they started dieing. I need to know how I should restock the tank though. I prefer small colorful and playful fish. I want a betta but im not sure if it would get along with the otto. Any advice?