Flowering problem

Hey all, first grow and first post. I am having a problem with flowering my 5 juicy friut plants. I have been on a reduced light schedule for almost over 4 weeks and I cannot see any visible signs of flowering, no hairs, no balls. I see a little growth that looks like a pistilate on my stems.
I have a 2 light fixture with four 48" flourecsent lights. The plants are over 3 feet tall, at least one is over 4 feet. I had them on a 12-12 schedule, but I scaled back to a 8-16 light/dark schedule two weeks ago, thinking that I should have some flowering easier, quicker. But, no luck! I am running out of verticle space. I need some help!

you should top them look in the grow FAQ and gool for FIM topping. Also you said that you switched it back to 18 / 6 if you did this you wont see flowering it needs to stay in 12 12 to flower ( 12 hours of light or less )

I have the girls (I think) on 8 hours light, 16 hours dark. So the light is far less than dark.

whay are you doing that??? Switch back to 12/12 and get more light, sometimes plants don't flower because there isn't enough light. If your plants are 4 feet tall then you need to get a 400 or a 600 watter to flower with.