I currently have a male convict in a 20 gallon with a few gold barbs, i wanted to add another convict but dont want the barbs killed? should i get another male or will both convicts fight? or should i gamble with a female?

Well, if you get a female and he wants to mate and she doesn't,he may kill her. If she wants to mate then you'll have a ton of babies and your barbs may get killed. I think 2 males would probably fight. 20g is not big enough for each to have their own territories. Either way I think a divider would be a good investment but I think you'd have better luck with a female. I had 2 males in my 55g and they did not tolerate each other at all.

putting two males together is a bad idea for most cichlids unless there is alot of space.... much more than you think they need.... for them to claim as their own. If you get a female and they begin to breed, the barbs will most likely get killed.... cons are notoriously aggressive when eggs or wigglers are present. For example, back a year or so, a TFF member had a huge 375G tank with an oscar, a pacu, and some other large cichlids (i dont remember the exact stocking), and when a pair formed from his school of 6 or so cons, they dominated the tank, keeping all the other occupants in a far corner and charging after them if they moved too far from the corner.

And as sheilaf said, 20G is too small for a pair of cons unless breeding, and if they do breed, it will be too small for them and all the babies after only a few weeks of growth. Either upgrade the tank size or just wouldn't recommend getting another con