I keep one of each in my 120 for quite a few months now, had 2 of the red ones but one decided to jump out when I was screwin with my tank. He survived for a month after that but haven't seen him for weeks and presume he's passed. They get along fine although I did hear the purple is more agressive! They swim about 5in away from each other and will criscross when feeding, also it's a good thing I got them on flakes.
