I have a 56 gal column tank doing just fine. I recently added 3 redline torpedo barbs to my community of swords(2), rainbows(3) & gouramis(2). all get along just fine. however, one of the barbs got sick and I couldnt save him, leaving only the two barbs. its been about three weeks and I was wondering if I could/should add one or two more torpedos to the tank or we good as is? I worry about upsetting the status quo.

I'm not familiar with this particular barb, but many barbs are best kept in schools and can become nippy if not. So, i'd argue in favor of adding a few, however, keeping in mind that a column style tank cannot hold as many fish as a same sized tank in a different shape, ie be careful not to over stock.

I think that's the same thing (Roseline barb/Torpedo barb). Without knowing much about this specific species, and based only on what i know about barbs in general, i would guess that they would be okay with the new additions. When you said column tank, i assummed it was a tall, narrow tank, but i see they also have "column" tanks that are basically a square. Which type is yours?

Even aggressive fish tend to leave plecos alone