ROck copper..

A plant will eventually show its sex.. regardless of the light cycle....
Usually this will be between 4-10 weeks....

There is really no reason to sex your plants now... just grow them to the size that you wish.. probably10-15 inches... and then switch them to 12/12

they will double in size over the next 2-3 weeks... after you switch to 12/12...
they will show their sex after 7-14 days.....

and 6-8 weeks later you will be harvesting!!!!

You can not tell the sex of a plant by the number of blades..

: )
happy growing!!!!!!!!