Green: you're asking a lot of questions that have some significant variables. How much you're going to get depends, not only on the type and strain you're growing, but the nutrients you're feeding them, the lighting schedule you're using and your growing style. From your post I'm assuming you're growing in soil of some kind and you've just switched to a 12/12 light schedule to start flowering them. That leaves us a lot of variables remaining.
I'm more concerned at this point with the color and intensity of the light you're giving them. I grow under a T-5 fixture that lights up my tent like a used car lot. For vegging I use blue 5,000 to 6,000 K grow tubes and for flowering I use 2700K and 2800K red lamps. I'm not sure what the lumens specs are on my T'5's but I can tell you that they're a lot brighter than any curly cues I've seen on the market. At this point I would suggest you change your lamps to something like a 2700K lamp which will give you the red hue you need for flowering and keep them close.
What I would suggest next time around is: start on a 20 hours on and 4 hours off light schedule under 5,000 to 6,000K blue lamps. Decrease the light by one hour every week which increases the dark by an our. At around 14 to 13 hours of light you'll notice some changes in your plants as they start to preflower, and it's usually right on shcedule. At that point I change my lights to 2700 to 2800K reds and their nutrients to 1/2 strength flowering formula for a week. If they like it, and they always have, then you go to full strength flowering nutes. I keep dropping the lights weekly down to 10 hours of light and 14 hours of darkness. I've had very good luck with this progressive light schedule under florescent lighting and I think this would be applicable to what you're doing. I don't know if it'll will work right now. I hope this helps. HSA