I have a 30g tank, with six Serpae Tetras, one male Bristlenose Catfish and one Balloon Blue Ram. The tank has been running for almost a year with all fish except Bristlenose full grown, we check nitrate, nitrite and ammonia every other day and since our tank was cycled have never had any issues.
My local aquarium is selling these beautiful Golden Balloon Rams though, and I was wondering if my Ram would like one as a friend?
Alternatively, I thought a red morph Honey Gourami might be nice, as all my fish live predominately in the bottom third of the tank.
We do a one third water change once a week and have many hiding spaces and live plants.

Also, I know Serpae's have a reputation for nipping, but I never seen them show any agression to anyone but each other, they school together at times and chase each other at times, but have never bothers Bristlenose or Blue Ram.