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Want to change my light cycle...safe?

Discussion in 'Absolute Beginners' started by DubSacAssassin, Jan 26, 2011.

  1. #1 DubSacAssassin, Jan 26, 2011
    Last edited by a moderator: Jan 26, 2011
    Okay I'm ready to flower the plants I have but I would like the lights to run at night to keep the room as cool as possible. I have the timers set for 6am to 12am for an 18/6 cycle but would like to run my 12/12 cycle from 8pm to 8am. What's the best way to transition from the 18/6 to the 12/12?

    I know it's a noob question but I would appreciate your time, thank you


  2. Turn the dials on your timer to 8pm on and 8am off. Serious answer with minor sarcasm.
  3. It's digital :p

    So no worries with them being in the dark for 20hours before switching to the 12/12 cycle?

    Time to clone!
  4. I'm going to need some backup for this because I'm not positive...

    But, I think you can run them from 6am to 8am and then just keep it off for that 12 hours until 8pm... then it runs to 8am... etc.
  5. Hmm it almost seems having it completely off for longer would be safer. Or am I wrong?
    Thanks for the quick reply chombie :)
  6. As you now start 12/12 you have to remember that it is the extended dark period that triggers the plant's hormonal reaction to flower. So, once you get out of veg you don't want to extend the light period. Therefore, don't let the lights come on at 6am and then run all the way to 8am the next day, that's 26 hours straight light.

    You could let the lights come on at 6am and then turn them off at 8am same day, so 2 hours light, then you are on 12/12 starting with your first dark period 8a-8p that day, or you could let the lights go off at midnight and then not turn them on again until 8pm the next day, 20 hours of dark would be fine. In fact, some growers purposely give their plants 24-72 hours of straight dark when they transition from veg to 12/12, believing that it will "kick start" the flowering reaction (this has not been proved or disproved, and if you do it or not the plant will still flower in 12/12 either way, it's just a debate about whether it gets things going a little quicker).

    Just remember in flower it's OK to shorten light or extend dark, never to extend light. In veg it's just the opposite.
  7. Thanks toasty! I've got the timers set to 8pm-8am with the lights turning off tonight at midnight to give them 20hours of darkness...hope it goes ok! I've been setting up my aeroponic and man I really miss the tranquil aquatic sounds LOL

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