Aaron, normally we have one male to two females, this is termed a trio for obvious reasons.
Why we do this is because the male can share his amorous desires with the two, thereby taking the strain from a single, that could get injured, killed, or even forced to escape from the tank if it's not covered completely.
Goodluck with breeding them, I'm sure Wok will have explained what you need to know about that fun time of the hobby.