I am not so sure about being able to tell by seeds, but here is a link that should help you while growing. Higher Female Ratio (Again..)

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Accept who you are and live how you're suppose to....that is freedom.

USEFUL LINKS

Marijuana Light Spectrum
Higher Female Ratio
Foliage Feeding
Drying & Curing Marijuana
Grow Room Ventilation
Usefullness of Males