Whenever the fry begin to nip at each other, usually this is the males,
     but some females might do this as well.  For growth, males can be 
     moved to 1/2 gallon bowls/jars While the females can be put together 
     in a large tank, just watch them to pick out the females that like
     to nip at the others and put them in homes of their own. Later when 
     the males and females have reached adulthood, you can move them to 
     quart jars, or leave the females in a big tank together.  Though if
     one female gets ill, she could pass it on to the other rather quickly.