18hrs Vs. 24hrs

The age-old question: 18hrs or 24hrs?
Although this has been widely debated in forums for years, I've never seen any concrete answers with factual information to back it up.

So I ask you all here at RIU, is there an advantage to vegging under 18 hours of light vs 24 hours of light?

Anyone have anything to say?

Go with nature man.. I did 24 and 18 hours and when doing 24 hours of light my leafs werent as healthy. The longest amount of hours the sun can be up for is 16 hours the most I believe the sun goes down for a reason plants thrive when everything is more natural, . Hence is why I will be doing 16 8 on all my next grows.

Well from what I have heard and read, the advantage of 18 hours of light is the plants will show their sex sooner. The advantage of 24 hours is more growing time. I personally grow 24 hours of light and once I get near flowering I go to 18 hours so I can weed out the males.

vein5 said:

Well from what I have heard and read, the advantage of 18 hours of light is the plants will show their sex sooner. The advantage of 24 hours is more growing time. I personally grow 24 hours of light and once I get near flowering I go to 18 hours so I can weed out the males.

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Is that an argument.. If you do 12/12 from seed plant will show sex in 2 weeks

This kind of an old thread but maybe we can open it up again.

I am running 18 hour days. It was a bitch to set up a timer that was cheap and off the shelf. I finally found one at Ace Hardware that had 20 set points. I will attach the setting I have been using. Growing Northern Lights the plant matured and grew to 20" in 55 days. The plants actually saws 70 days worth of cycle. From what I understand this is not remarkable but a good growth rate. I am now in the flowering stage so I do not have anything to report on yield.

I personally do only 24/24, and I believe that the only difference if I do 18-6 will be slower growth rate by 25% because vegging plants will just keep growing as long as they receive light.

Lol stick with nature.. if humans had stuck with nature wouldnt be global warming

I have run my veg tent for over a year with 24/7 lighting and like the faster growth I see. I have done 18/6 and 20/4 but like the 24/7 best. Always good and green with no problems.

people see what they want to see so lets agree to disagree

bombasticson said:

Lol stick with nature.. if humans had stuck with nature wouldnt be global warming

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if people had stuck with nature, there would no mass production of food, we would have been no more than 2billion tops inhabiting the earth, and we would probably still be with stones and sticks

24-7 veg if you can afford the electric bill!! If your leaves didnt "seem' as healthy they they were prolly lacking some nutes! ... aggressive lighting requires an AGGRESSIVE feeding schedule!

no plants need time to sleep because that is when they repair themselves and process sugars that develop during the day

bombasticson said:

no plants need time to sleep because that is when they repair themselves and process sugars that develop during the day

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Source? I've heard that during the dark period the plants put more energy into root development, but I've never heard of people saying that the plant exclusively processes sugars during the dark hours or that they repair themselves only in the dark.

While I agree that plants need some rest time I don't think it's for the reasons you posted. There's been tons of debate on 24/0 vs 18/6. I would go 18/6 or if you want to meet bomb halfway go 20/4.

Saying that we should copy nature is like saying human ingenuity is stupid.

I believe both18hrs & 24hrs have there benefits, it mainly depend on your set-up.
I personallyrun 18hrs due to my DWC cupboard set-up – I run a 600w Retro MH for Veg & findit easier to maintain room & res temp with some lights off time & mygirls still manage 1” a day.
I have run24hrs but for me the ladies didn’t look as good, still health but not as lush, Iwould try 24hrs again but only if I changed to CFL or LED.

Plants need darkness period ~

bombasticson said:

no plants need time to sleep because that is when they repair themselves and process sugars that develop during the day

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Dark reactions can happen in the dark not must.

http://en.wikipedia.org/wiki/Calvin_cycle
http://www.wiley.com/college/boyer/0470003790/animations/photosynthesis/photosynthesis.htm

maybe if you buy your plants a present they will be nicer to you lmao. JK guys.

I'm doing 18/6 veg cycle cause it just feel more natural to me. Sleeping feels so good to me, I want the same for my baby's