I have to agree, tiger barbs are definitely a limiting fish. You can see from my list below, however, that I've been able to keep them with rummy nose tetras--sometimes they school together, sometimes not. My sense is that everything has to do with personality and numbers. I quarantined one of the barbs for a day (long story), and suddenly one of the barbs turned into Dr. Evil and terrorized the entire tank. They are cool fish, though I'm considering returning them in order to have more options in the tank.