Totally having an anxiety moment with trying to decide how to switch from veg to flower do switch to 12/12 when the light turns on aftter normal schedule or after lights go off do i wait 12 hours then do 12 or??? Also read something about 36 hour dark period? If someone could give me step by step instructions thats be great as to what time to switch the light etc etc....
I just go from 18/6 right to 12/12. Walk up unplug my timer reprogram it quick plug it back in and done. My veg times are 12pm to 6 am and flowering I do 12pm to 12am. You can flip whenever you want. I have read that putting it into darkness for two days will speed up the initial switch to flowering. Before you flip to 12/12 I would suggest giving your plants a few plain waterings to get the veg nutrients out or you could possibly see some problems.
It doesn't matter exactly when you change as the plants take a week to even know the lights have changed. The 36 hour blackout brings up the flowering hormone in the plant and takes a few days off the change to flower. BNW
Some but not all people do a 24,48, or like was mentioned up to a 36 hour blackout all dark period right when they change the light cycle to 12/12. It supposedly brings on flowering faster. I don't do it myself but personally 36 hours seems like too long to leave them in the dark with no photosynthesis. They don't uptake nutrients in the dark. Average time for my crops to show flowers is about 7 days without the 3 day wait period of dark. I just decide when I want the light on and off time to be. Sometimes it's very strategic to your whole operation. You want it timed so the lights are on when you have time to check on them but in some areas there is an off peak electric usage rate that is lower then the high demand part of the day. Also if you run your lights at night it helps offset the hot part of the day for better overall grow room temps. You won't have to compete with the high temp to cool your lights, only nighttime temps which are a breeze comparatively. Having them come on about 8-9pm is a good idea. Then they're off at 8-9am. If you can't fit in an evening feeding/maintinence session just hit them up in the morning. You'll be running the lights during the coolest part of the day.
It doesn't matter if the plants receive a short or long day or night when you change. They won't care, just change the timer whenever is convenient for you
