I keep all predators from 5" to 27" amongst 7 tanks.
I have many 'supposed killers' like 26" giant snakehead, 19" aimara wolf, dorado, gatf, armatus vampire fish, asian red tail, alligator gar,
25" tem p-bass, 23" pacu etc
but the most aggressive is not supposed to be aggressive -its nice pink rose queen i bought for my gf ( her name is rose) which is about 13-14".
so far it has killed a 12" buttokofori, a 16" giant snakehead, and ragged my 26" snake head and 19" aimara wolf and various p.bass!!!
ive had to put him on his own in my 5ft tank. he is totally nuts. im i put my hand in the tank to adjust filter he goes for my hand straight away.!!
Dont be fooled by pretty looking pink fish- they are are not as nice as they look !