If you don't have the space to bend them and still be in the light your in the same boat I am.All of mine are orange bud but one wants to be a monster twice as big and I didn't want to get the light too far from the others. I had to cut the tops off the main cola and a bunch of stems after 12/12 for 3 or 4 weeks. It just grew up in to the light and burned any way. If you can't bend them then cut off the tops. Your looking at them going double the size when you go 12/12. Remember this too. If you only have top light your only growing the top 1/3rd of the crop anything below this will not get enough light for good buds. Take a look at my new thread in hydro. (redhair Ladies). The top I had to cut are all narly looking. I just put a 1000 HPS on them last night for the last 2 weeks of flowering . I hope it swells them up. Bend or cut unless you can lift each plant up on a pedastall to make them the same hieght. I'm just now understanding that in small grows that the 12/12 should be started at 4 or 5 nodes. You want short plants with huge bud on them you acually get more than growing trees because of the light. My next grow will be started at about 6 to 8 inches and end up at about 18 to 20 inches with a big fat bud on them, then light gets to all. Also growing different strains at one time cauuses prob's like this. Live and learn. show us some pictures we all like to see good growing plants and some one might have a better idea for you.