Everything will be fine... when he gets to like a foot then i would start to worry about the balas but the oscar has absolutely 0% chance of being eaten because first of all he will grow faster than the lima and second he is to tall for any lima to choke down...
Lovethejack: u have a good point which I also have thought of tht being that oscars get really tall which I think it would make it hard for it to be ate. Also I'm trying to get the lima early so that way they all grow up together.