Pacu, some piranhas, african cichlids, flower horn. Pacu are just ugly fish. I've kept them before, even at large sizes there dull with little personality (in my experiences) also they look like an old mans as,s. some piranhas (red belly mostly)(Exclude blacks and elongates) are also dull. most of these fish I've just had bad experiences with. africans because i loved the way they looked and interacted so i bought 5 syn petricolas and some others. most of the time they don't have much colors except the yellow lab which is just shy. the petricolas are terrified of me and i rarely see them. flower horns because i think they are two unreliable when you buy them young as in which color your going to get. also its just not my thing. maybe in the future. also the fact i can't have a big tank larger than a 125.