This is almost totally up to you.
If u feed then loads of newly hatched brine shrimp 3 time a day then you can have fully grown fish with in 3-4 months.
Feeding flake food 3 time a day will give good growth rates but to get to adult size will take 6-8 months and they sex out (at 4-6 months) their slow down even more, as breeding become more important the growth.
Separating the male away from the female help to speed up growth rate's.