Best age to start breeding guppies?

[Cichlidsrule]

I have six approximately four-month-old guppy fry, which have just begun to show their colors. I've heard they become sexually active at six weeks, but is that too young?

[doggydad38]

My juvie Guppy males actually start chasing and displaying at about 6 weeks. You won't start seeing fry from the females until somewhere around 3 months, if you keep the sexes together. Some lines develop more quickly than others, some are slower. Most pro breeders don't set up their breeder fish until about 4 months of age. This allows both sexes ample time to grow out so the best can be used. As I said before, some lines have to be bred at an early age or it becomes more difficult to impregnate the females. 3/4 Blacks are notorious for that. Hopes this helps.
Tony