18hrs Vs. 24hrs

Ender87i

Ender87i

Well-Known Member
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?
 
bombasticson

bombasticson

Active Member
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.
 
V

vein5

Active Member
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.
 
bombasticson

bombasticson

Active Member
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
 
Glider

Glider

Member
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.
14 on- 4 off watering cycle.JPGIMG_0468.PNGVeg cycle 14 on-4 off.JPG
 
zem

zem

Well-Known Member
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.
 
BatCave

BatCave

Well-Known Member
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.

 
zem

zem

Well-Known Member
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
 
N

nastynate420

Active Member
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!
 
bombasticson

bombasticson

Active Member
no plants need time to sleep because that is when they repair themselves and process sugars that develop during the day
 
Cloudz2600

Cloudz2600

Well-Known Member
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.
 
D

.Da1&only.

Member
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.
 
D

.Da1&only.

Member
With all thechemicals like Enzymes, Root promoters & Hormones ect. I don’t think theydo need sleep, I think the plant will look healthier with darkness tho. PersonallyI have mates that only run 24hr set-ups and they aren’t getting better yieldsthan me….
 
BlueBalls

BlueBalls

Well-Known Member
bombasticson said:
no plants need time to sleep because that is when they repair themselves and process sugars that develop during the day
Click to expand...
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
 
Geronimo420

Geronimo420

Well-Known Member
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

Sleeping puppy.jpg
 
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