I've got a friend getting rid of his black ghost knife and i want it. I only have one freshwater tank running and that has my aro in it. It is a 270 gal. tank with my aro, some neon tetras (If I loose them its not a big deal) a pleco and a cory cat. (my sds slowly bacame aro food) Will the aro and the bgk fight? The aro has already eaten some fish so I'm nervous. But the bgk is 7in. and the aro is 7-8 in. I have had bgk before and he was'nt agressive but what do you guys think?