Changing Flower light schedule

What’s the best way to change my flowering room (3 wks in) to a night time schedule? I need the lights to be on from 8pm to 8am. Presently the lights are on from 7am to 7pm. I’m running ceramic metal halide and Summer is about hit us.

If ur in veg still should be good to leave them on til desired time to go off then keep on that timeline. @Hoppiefrog is a cmh hps fella

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May just need to do a 25hr dark period. When the lights go out at 7pm keep them off until 8pm the following day


These plants are starting their 4th week of flower. Is it still possible to change their light timing?

@Mark0427 Thanks so much for replying!!
These plants are in their 4th week of flower. Now what? Can I still disrupt their schedule and do no harm?

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Ooh let maybe @dbrn32 @Covertgrower @MattyBear @Myfriendis410 someone with more knowledge ring in first. I thought was still in veg stage. Might make a difference might not. Hoping best for u buddy. Good luck. Wish i had the answer for u. One of these guys will tho.

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Just extend dark period until you reach new lights on time.


Ok so i had it backwards then?? I said leave lights on til the desired off time. But thats when i thought in veg still. See wiser words lol

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I agree, run longer dark period then resume 12 hour light schedule at new time.


Best to plan that one out ahead of time, idk if I would change the schedule fast at all at that point of the game, 3 mins on either end of day (per day) max.its a lot of work but you won’t get a room full of Hermes at least

This is unnecessary, and if a 13hour scotoperiod coincided with hermaphroditism, that plant was gonna do that anyway.