guppy fry maturity

[Fishy3]

I have a dozen 5 week old guppy fry all housed together. My question is, when do I need to start trying to seperate out the males and females? They are all from the same batch and I do not want any inbreeding.

 

[Tokis-Phoenix]

Start separating as soon as the males start showing definate signs of becoming male like the development of their sexual organs/shape of bottom/underneif fin, just take which ever male does this and put him another tank or put a divider in the current tank to separate them .
You should start seeing signs of the guppys becoming male at 2-3months old- all guppys appear female when born but change as they mature if they are going to be male, watch out for late developing males too .