[JustJen]

I'm speaking from a friend's experience, not my own, but she has a full grown red severum in her 90g community, and he is one of the more peaceful fish in her house. He's active and personable, but totally ignores everyone else in his tank (angels that started out tiny, glowlights, swords, dojo loaches, bristlenose plecos, etc) and always has. It's a heavily planted tank too, and he's never caused a bit of issue in that regard either. Maybe from what others have said, it just depends on the fish, but based on what I've personally seen, I wouldn't have any issue putting the rainbows with one.

 

[JustJen]

Out of curiosity, might I ask what some of the plant species are in the tank with that severum?

A variety of lowish light/low tech stuff - an absolute jungle of corkscrew val, various crypts, some ludwegia of some sort, dwarf sag, I think some cabomba, and probably a few other things, but as it's not my tank, I can't remember off the top of my head