It all depends upon how knowledgeable u are on atf. If ur a newbie, go with 1 nice tiger. If i was u I'd go with a goliath. If ur tempted for a school, ur gonna need a min of 3 better off with 5 as well as some dithers, like tfb or sd. Better off with tfb. Aggressive feeders and can take a beating np! Make sure u have high o2 and filtration! It's a must. U can power feed with live til they reach 6" then definitely switch it to nonlive. I've had good luck with mp or tilapia chucks as well. If u can get them on pellets, even better. U have to do ur best to cut their aggression down amongst themselves. It's a natural habit but hopefully in a big group u will be able to cut it down. The issue is , is that they aim for each others eyes, and can do damage. Once that happens, u can lose the fish. GL!!!