So my girlfriend just moved into a condo with her mother and sister. In her room, she has a 50g tank built into the wall. And naturally, I'm the one who has to take care of it. Go figure. Ha. But anyways, my question is, what could I put in there that would be very vibrant and not too terribly aggressive? I was thinking maybe 3 or 4 Severums. Would they be comfortable in a tank that size? Any and all suggestions are welcome. 