Flipping 12/12

[Smokesteve]

So I'm on day 2 of dark on 12/12 I want to flip my light on and off by basically 12 hours. I really don't want to screw this batch up they look so great! So what is the least stressful way to go from light on during the day to light on during the night if there is any. Thanks

[Campesino]

You want to move the start of the light period by 12 hours?
You could move it a little, but these are things to think about before flipping not after. I don't think you can do it quickly without stressing the plants. Slowly - over the course of 3 weeks you could run them on 11.5 light and 12 Dark. That will take 24 days to complete the transition. It shouldn't stress them too badly, but will probably affect their circadian rhythm

[Smokesteve]

Wow even though this is only my second darkness period? Day 2 in darknesss right now I could keep it off for an extra 12.

[Campesino]

flipping to 12/12 is already the most stressful thing we do to the plants. On their 2nd day of 12/12 plants are probably as stressed as we will ever make them (in normal circumstances).
Rather than extending the darkness further (even more stress). The alternative I'd suggest is going back to 18/6 for a week and then starting 12/12 on the correct schedule.

[DoctorJohnson]

I'm curious what you mean by "day 2 of dark on 12/12." Surely you haven't been giving your plant total darkness for two days?!

Don't overthink it, man! It's just a weed!

[Smokesteve]

I mean second 12 hour dark period

[Weed Pharma]

It's the darkness that matters- just continue the dark- lights off, until you want the lights on period to begin.
One light schedule change, anytime during flowering, won't affect anything.

[Campesino]

The plants would survive 24 hours of darkness and an abrupt flip of their circadian rhythm, but it would not be "Stress free".
Plants don't just respond to the conditions around them. They develop endogenous rhythms and predict (and prepare for) the light and dark cycle. Altering their rhythm suddenly stresses plants (Including when we flip to 12/12).
The link I posted is pretty interesting...

[Weed Pharma]

My addition to the thread comes from personal growing experience, when faced with the same issue on more than an isolated instance, replicating positive results each time.
Some routinely place the plant in complete darkness for 24-36-48 hours upon entering flowering, but I wouldn't recommend anything I haven't experienced.

Campesino, There are many ways to get desired results-and I encourage you to follow your beliefs.

ps. (I have used the method you mention before , as well)