The one thousand and one sex my festae thread.

Females can be ready at 4", but conditioning, whether the tank provides acceptable, stress free breeding sites, and whether male(s) provided are actually acceptable to the female all come into play. Just because we humans think we have provided a perfect mate, doesn't mean the females do.
Although larger males will in many instances kill a female, those males are often the preferred partners, because they are seen by the female as most qualified to defend a spawning site, and young.