Just going by my experience with my black aro at around 17-18". She never went after the cardinal tetras when I kept them with her. When I tried the congos I lost 4 in five nights. Seemed the congos where big enough to make a meal and the cardinals just were not worth it.
She is now in a tank with a bunch of serpae tetras, I don't think she is munching on them, but someone is I've lost 6 over a 3 week period. Probably the pimelodus catfish. Going to remove it and the sevrums and add some cardinals to the mix
She is now in a tank with a bunch of serpae tetras, I don't think she is munching on them, but someone is I've lost 6 over a 3 week period. Probably the pimelodus catfish. Going to remove it and the sevrums and add some cardinals to the mix

down to 3 congos lost 4 to the Jar I believe it was due to getting him off the fresh shrimp to sinking carnivor and food sticks but all has been good for the past weeks since he has taken to the sinking carnivor dont think I will add anymore congos the convicts have bred a while back and attack the jar bad news is he attacks back and the convicts must stay hidden in the wood, the jar does not attack the fry though??? thinking of adding some neons but not sure they willhang wih the congos. anybody got ideas of who will school with the congos other than congos and smaller sorry for spellings or whatever but Im kinda drunk typing lol thanks...