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18 or 24 hours of light

GHETTO_grower

Active member
WaywardBob said:
3 of my 5 plants showd sex in 20 days from seed under 24/0.. i thnk thats pretty good isnt it? maaybe i had to genetics, never gone 18/6 before tho..



hahaha took forever to reply, but thats because you were doing a great job with your plant , but it also does also depend on the number of internodes and genetics I've read now these days
 
G

Greyskull

I work my bitches in veg 24/7 under a 400mh. They can sleep when the lights go out in flower. I am in charge of my bitches. :pimp3:

My plants are ready to flower faster, and more improtantly the internodes are tighter.
 

vince514

seeker of greater knowledge
Veteran
24h=faster growth..........18/6 provides lush even growth but 24/24 means that you can veg faster instead of(example)...4 weeks of 18/6...2 1/2-3 weeks of 24/24 and that means you can put your girls in 12/12 quicker......but remember that your bulbs need a rest eventually.............peace
 
G

Greyskull

I have done it... I don't like the leggy 18/6 growth compared to the beefy 24/7.
 
G

Greyskull

threads like this truly exemplify the best thing about cannabis is that anyone can grow it pretty much anyway they want... you can work it like a bitch or treat it like a princess... and it doesn't matter because it will grow pretty much regardless.
its impervious to personal preferance... it just wants to grow.
 

vince514

seeker of greater knowledge
Veteran
libby said:
Confirm you have done this ?



.........yes in fact i have i usually doit with seeds for the first 60 days of their life....believe me they grow FAST...faster than if they were18/6....but then again....here's a pic of some seedlings their just about @ the 60 day point after i clone em i'll switch back to 18/6.... some pics...







....their lush.....24/24...but after cloning i switch to 18/6 to avoid any un-needed stress to the plants.....peace.... :joint:
 

HobbyGrower

Member
This is a direct quote from Ed Rosenthal whom most of you know is a marijuana growing guru:

Marijuana plants photosynthesize as long as they receive light as well as water, air, nutrients and suitable temperature. Photosynthesis is the process in which plants use the energy from light (primarily in the blue and red spectrum's) to combine carbon dioxide (CO2) from the air and water (H2O) to make sugar while releasing oxygen to the air.

Plants use sugars continuously to fuel metabolic processes (living) as well as for tissue building. The plant combines nitrogen (N) with the sugar to make amino acids, the building blocks of proteins. They are the substance of plant tissue. When the light is off, the plant's metabolic processes, respiration and growth, continue.

The plant can photosynthesize continuously so it produces the most energy and growth when the light is on, continuously. Continuous light does not stress the plant, which reacts somewhat mechanistically to it.

Plants under an 18-6 light-dark regimen are producing sugar only three quarters of the time. They are thus growing at only 75% of their potential. Leaving the light on continuously will result in bigger plants, faster, which leads to higher yields."

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"The following information is straight from Greg Green's "The Cannabis Grow Bible"

Cannabis is a light demanding plant. Professional growers keep the light on their plants using the 24/0 photoperiod for this reason. Plants that grow under 24/0 flourish and do not need a quantity of darkness in order to rest and perform photosynthesis properly. Plants that are grown in optimal conditions under 24/0 light regime grow vigorusly and the benefits of a 24/0 photoperiod can be seen actively in the results. More nodes are formed, more branches are created, leaf numbers increase, the plant is growing at its finest.

Some growers opt to use 18/6 as their photoperiod. This is 18 hours of light, six hours of darkness light regime. Under these conditions the plant will grow quite naturally but not as vigorously as the 24/0 photoperiod.

The 18/6 photoperiod expels 3/4 the amount of light that a 24/0 photoperiod does. Although this does not mean that a plant produces 1/4 less leaves,branches and nodes under the 18/6 photoperiod, it certainly does show the correlation between light and cannabis growth. As we have said already, cannabis is a light demanding plant. There are no problems associated with 24/0 and although some have attributed cannabis sexual dysfunction (the hermaphrodite conditon) to 18/6 photoperiod these problems are actually the result of heat stress.

A 24/0 photoperiod requires that your grow room temperature be kept well monitored. The 18/6 option is cheaper to run. You use a quarter less electricity and this will have an impact on your electricity bill. Also the 18/6 photoperiod will generally extend the bulb's lifespan. During the 6 hours of darkness the grow room is allowed to cool down for this period but a well maintained good grow room setup should not require a cooling down period.

24/0 and 18/6 both share the same problem though. Once you start the photoperiod you should keep that way especially when the plants near maturity (the preflowering stage). An irregular photoperiod can cause more males than females to develop. It can also cause sexual dysfunction to appear. Whether you choose 24/0 or 18/6 as your vegetative photoperiod try to keep that photoperiod unitl your plants are mature enough to express their sex."

TLDR: 24/0 is superior insofar as plant growth
 

chaz

Member
im a fan of the 24 on cycle.ive done a side by side with white rhino.24 hour cycle used a lot more watering(obviously)but was more sensitive to fertilizing.the 18 hour cycle was darker green by a few shades but smaller by about 30%.not to mention the roots.holy crap,the roots were out of control.i had to abort the test early,meaning i had to transplant and giving it fresh mix would throw off my results.happy thanksgiving y'all!
 

Frozenguy

Active member
Veteran
I just dont really buy into it.

I think every living thing benefits from darkness at some point.
Find me one animal that doesn't sleep to some degree.

Sometimes I'll run about 20/4, then for the week leading up to flower I go 18/6. Otherwise its all 18/6.

People get results with 24h though.
 
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Frozenguy

Active member
Veteran
This is sound logic if we are growing goats.

I grow marijuana, so it does not apply to my situation.

It may not apply to your situation. I was not using it as a sound argument for plants, but merely showing how the night cycle seems to effect everything; except plants?

I wonder why plants are so alien that they derive no benefit/need from the night cycle.
 
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I wonder why plants are so alien that they derive no benefit/need from the night cycle.

One of the many mysteries of life.

Think about it this way:

I deprive my plant of sex, natural plant food, real earth/soil, sunlight, weather changes, insects, birds and paid vacations. Yet, it thrives better in my grow-room then it would in a natural environment.

Plants are not goats.
 

Frozenguy

Active member
Veteran
One of the many mysteries of life.

Think about it this way:

I deprive my plant of sex, natural plant food, real earth/soil, sunlight, weather changes, insects, birds and paid vacations. Yet, it thrives better in my grow-room then it would in a natural environment.

Plants are not goats.

:rolleyes: :rolleyes:
Your ignorance is amazing.

Plants use photosynthesis to convert light energy into chemical energy. Plants cannot photosynthesize at night, so during the day, they devote their cellular machinery to little else. When the sun goes down, they switch off the genes that encode proteins used during photosynthesis and switch on the genes that express proteins involved in growth and cellular damage repair.
http://www.hhmi.org/news/chory20080213.html

Just because something is completed doesn't mean its a quality finished product.
I've noticed that plants grown with a dark period tend to have thicker and stronger trunks/branches going into flower, as well as tighter nodes. But you can keep depriving them even though they flower and finish.
 

Dr. D

Active member
Veteran
This thread is 6 years old!! lol
Thanks for the info Frozenguy, personally i run 18/6 becasue i prefer it and its less on the electric but i just started running 24/0 again in a small veg tent for revegging and for my males ( i have problems with some males autoflowering at 18/6) ...that article is quite interesting considering i run my lights at night in flower, i do have a daytime flower tent too but no difference so to speak that ive noticed. has me wondering if there is any effect....
 

Frozenguy

Active member
Veteran
This thread is 6 years old!! lol
Thanks for the info Frozenguy, personally i run 18/6 becasue i prefer it and its less on the electric but i just started running 24/0 again in a small veg tent for revegging and for my males ( i have problems with some males autoflowering at 18/6) ...that article is quite interesting considering i run my lights at night in flower, i do have a daytime flower tent too but no difference so to speak that ive noticed. has me wondering if there is any effect....


LOL I didn't even realize how old this thread is. Thank god it wasn't my doing lol..

Yeah from what I gather from other articles and stuff done by Dr. Steve Kay, is that the plant gets cues for its clock from the light. So as long as you have darkness, regardless of when, the plant will build a clock off that regimen.
 
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