If not breeding pair,,one or the other will dominate and stress related problem's can be the result.
These fish do better in large tank's where water chemistry is more stable, and also do best with several specimen's at approx same size.
Hey thanks guys. I'm not going to get none but if I ever get a 55g or bigger that's when I'll get some.
Even in a 55g its iffy. Long tank, small width/foot print. 75 or a 90 which are both 48" long like a 55, except a 75, and 90 have 6 more inches of depth, 90 has more height over a 75. I'd buy one of them over a 55 while staying with the same foot print if thats what works for you best.