i'd also classify columbians as semi aggressive. it really just depends if you give them a nice sized school or not. i've seen them get bullied by serpaes and then a few days later, the serpaes were doing the nipping (not unusual for serpaes btw). the columbian r/b tetras are very aggressive eaters though. kinda like diamond tetras. they're always the first ones to the food.
but i'd say if they've got enough cover, swimming space and a school of 5 or 6 you should do well.
Last edited by rileynapalm; 02-15-2013 at 10:41 PM.