Tried something different this year and am trying a scrog grow. I am not sure when to flip into flower due to stretch. Do I let the canopy totally fill up or do I flip and anticipate the stretch to fill in the canopy. Here is a 2 week old video of my set-up and you can see I am not quite filled in, however now 2 weeks later, I am almost filled in but there are some bare spots.
I don't let my entire canopy fill up before I flip. I know exactly how much the strains I run stretch and know that they will fill the space by the time they are done stretching. I usually continue to tuck them under the screen until the first week into flower, and then let the rest of the stretch allow them to grow 12-18" above the screen. Without seeing what they presently are at and making assumptions about their growth from that video, I think you would be good to flip. The spaces that you are talking about will definitely fill in.
There is not an exact time when to switch but keep in mind that your plants will just about double in size when switched from veg to flower. Just make sure you keep enough room for that grow to make sure you stay away from mold and other problems when the plants get crammed together tightly without the proper airflow. Besides that good luck with your grow and hope you have a great harvest!
couple things I would change if I were you. (just some ideas from a fresh set of eyes ): screw that light rail, add more lights and watch your plants EXPLODE!!! youll cut down on veg time DRAMATICALLY and flower will be REDICULOUS I see air cooled hoods but cant see if there is glass in them, if there is, take them out it looks like youre making CO2 AND exhausting the room(good thing you have the controller ) Id run a couple more lights and run them in line with the fan to keep them cool and possibly lower the temp of the room put ballasts OUTSIDE the tent if possible to cut down on heat skip the trouble of SCROGing and just do LST or even HST. You have plenty of room for this hope this helps
Adding more lights may not work for their situation. 85 degrees is perfect for a tent that is running around 1500 PPM CO2. I disagree about the LST/HST, but that's because I love ScrOg. To the OP, do you have warm air venting outside of the room? If so you are probably using CO2 inefficiently. But if you did stop venting the warm air out and take off the glass, you will obviously have higher temps, so weigh your options.
air cooled hoods used properly would bring his temps down. Hes already got 2 hes not using I have a feeling hes gonna vent the lights from outside the tent to outside the ten(yes both outside) and continue using CO2