3 weeks 12/12, no pistils

I've had 8 big bangs and a nemesis flowering for 3 weeks now and none of the big bangs are showing any signs of sex. The nemesis started showing pistils 2 weeks ago. they were 4 weeks old from seed when I switched to 12/12 and i gave them 2 days of dark before the switch.
Does anyone know what's taking them so long or what i can do to help them?
The first pic is my setup, 2'6"x2'x2', 125w cfl with netting to stop anything getting too close, 4x18w tubes and intake/extraction fans keeping temps in the mid 70's, the next two are the big bang and the last two are nemesis.

bump. anyone?

Do you have any light leaks?? And somtimes they just take forever especially if its a unstable strain. I grow ALOT of my plants from bagseed and they commonly do this.

Also remember females tend to take longer so this my be a good thing.

try checking in the corner of the nodes where a fan leaf meets the main stock near the top of the plant.

heres a pic of mine

definatly check for light leaks this happened to me and i noticed some leaks in my closet and my room lights were on alot being as i stay up late.
some black tarp fixed me right up.

make sure no light leaks and just be patient

Patience is what you need.