Just want to clarify for him since he says it needs tankmates but then it'll kill anything. When younger tankmates aren't necessary but beneficial, as any fish does when small, they shoal for security and dithers help ween atf off of live. As they get larger they grow out of this behavior and become territorial wanting their own space which is when they begin to attack other fish. Aggression is rarely reported in gatf though. I believe it's because so few make it to a larger size where they would really be territorial.