I have a VATF in 6,5 . (maybe it is a FATF)
He allways try to bite in the fins from his Tankmates ( Scomberoides, Polypterus, Gars ).
Also every fish in the tank wants to bite him when he is swimming around.
I think they are freaking out because of his speed combinated with the silvery color .
I had to seperate him from my main tank and i will not try it again.
If you add a powerhead with a strong enough current, your ATF's behavior will change completely. He / she will just be at one spot trying to swim against the current.