People tell me not to mix them, but they all have been living together in the same tank for a long time, all active + healthy, they all eat like pigs, they fight sometimes, but harmless, I change water 50% once every 1+ month, I’m not into fishkeeping, I just keep fish alive for wife to watch, There was a pure black discus in local fish store, ick+plague+fallen rotten fin tail, I took it home and saved it, it's now active+healthy again, now he's the Alpha fish, the oldest fish are 5+ years old in the tank, that's when i started keeping fish