Wellllllll...If you have a large spawn you will probably have to divide it into 2 growouts... As soon as they start chewing on each other you will have to separate them into their own quarters.. Realistically, you are lookin at 6 months before they have enough finnage to be sold at the LFS...Young specimens have smaller less developed fins and dont sell well....
Regualr water changes (atleast every 3 days) will help speed their growth..