DaddyPaddy
Member
Always replicate mother nature, she knows what she's doing. 
24/0 vs. 18/6 debate is over!!!!
- Thread starter mafuki
- Start date
Mr.GreenJeans
Well-Known Member
EXACTLY!!!!! (+rep!!) I've argued with so many internet "experts" about this, that I finally just gave up and said let each do his own thing. Using 24/0 during veg cycle gives you MUCH bushier plants and shorter internodes.
As to the whole bullshit line about power useage --- well, you MIGHT use marginally less power (although I have personally never had a power bill increase due to my 600 watt HPS, but if you are running multiple 1000 watt lights I suppose it possibly might be a consideration) but unless you are a LARGE scale commercial grower you will not notice any difference on your electric bill --- plus that is negated by the decreased life of your bulbs caused by being turned on/off every day (bulbs last significantly longer if they are left on than if they are cycled --- it's easier for them to maintain a state than to go through the whole start-up/shut-down every cycle. Of course for flowering this is just unavoidable). And letting the ballasts cool for a while each day is not a bad thing, but if you have a decent system that is never an issue to begin with because the ballasts never get that hot to start with (mine STAY cool to the touch at all times, regardless of how long I run them!).
Anyway, excellent thread!! Some will find their assorted "reasons" why to go with 18/6 or whatever else cycle floats their boat, and that is fine. But if they are growing indoors and height is an issue at all (and they don't want tall, skinny plants) then 24/0 is an entirely viable and beneficial option.
And don't get me started on the village idiots who think that their plants need the dark time to "rest".....................
mafuki
Active Member
Thanks for the rep Mr.Green jeans
This is not "theoretical" i Have written this statement based off the factual plant studies that have taken place in "REAL LIFE" and speaking with numerous seasoned and pro growers with experience and all the info i have stated can be backed up if you look further into it and check out how a Class C3 plants function. Let me address the light issue first: Every time you turn on the light the starter kicks in and the more you turn on the light the more the starter is having to be worked out and the most common reason for HID light failure is the ballast starter dying therefor the less you turn on your ballast the longer your starter will last and you may say "well the heat becomes an issue when left on for a long time" well most people have some sort of exhaust system for their light to expel excess heat and if you don't then you shouldn't have a HID light on in the first place.
And now to answer your "Respiration" issues: I found this study on respiration done in a study at the U of Colorado at boulder and here is the link as well if you would like to check it out http://www.colorado.edu/eeb/courses/1230jbasey/abstracts/1.htm : "while cellular respiration predominates in the dark (although it is a continual process). meaning respiration occurs "during the light hours as well as during the dark hours.
I have also found the following to useful in my study-
"It's been established for many many many years now that cannabis is a C3 plant. It does not need a dark period.
C3 plants gather CO2 only during the light period when they are photosynthesizing. As long as the light is on, C3 plants gather and use CO2 for photosynthesis.
Some growers practice a version of anthropomorphism with their plants. They believe that since people need rest, plants do as well. Concerning cannabis, this is not true.
Every grower can make a personal choice about light cycle. They can save on their electric bill or prolong ballast/bulb life. 18/6 can be less of a "shock" when changing over to 12/12 for flowering than 24/0 or heat issues can be addressed by fewer hours of light, but basic botany has proven long ago that cannabis needs no dark period.
Ed Rosenthal, Mel Frank and Robert Clarke all have covered this extensively over their careers.
www.mellowgold.com/grow/mjbotany-removed/marijuanabotany1.html Marijuana Botany Chapter 1 - Sinsemilla Life Cycle of Cannabis
/www.cannabisculture.com/articles/3127.html Need the dark
-------------------------------------------------------------
"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."
-------------------------------------------------------------
"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."
This is not "theoretical" i Have written this statement based off the factual plant studies that have taken place in "REAL LIFE" and speaking with numerous seasoned and pro growers with experience and all the info i have stated can be backed up if you look further into it and check out how a Class C3 plants function. Let me address the light issue first: Every time you turn on the light the starter kicks in and the more you turn on the light the more the starter is having to be worked out and the most common reason for HID light failure is the ballast starter dying therefor the less you turn on your ballast the longer your starter will last and you may say "well the heat becomes an issue when left on for a long time" well most people have some sort of exhaust system for their light to expel excess heat and if you don't then you shouldn't have a HID light on in the first place.
And now to answer your "Respiration" issues: I found this study on respiration done in a study at the U of Colorado at boulder and here is the link as well if you would like to check it out http://www.colorado.edu/eeb/courses/1230jbasey/abstracts/1.htm : "while cellular respiration predominates in the dark (although it is a continual process). meaning respiration occurs "during the light hours as well as during the dark hours.
I have also found the following to useful in my study-
"It's been established for many many many years now that cannabis is a C3 plant. It does not need a dark period.
C3 plants gather CO2 only during the light period when they are photosynthesizing. As long as the light is on, C3 plants gather and use CO2 for photosynthesis.
Some growers practice a version of anthropomorphism with their plants. They believe that since people need rest, plants do as well. Concerning cannabis, this is not true.
Every grower can make a personal choice about light cycle. They can save on their electric bill or prolong ballast/bulb life. 18/6 can be less of a "shock" when changing over to 12/12 for flowering than 24/0 or heat issues can be addressed by fewer hours of light, but basic botany has proven long ago that cannabis needs no dark period.
Ed Rosenthal, Mel Frank and Robert Clarke all have covered this extensively over their careers.
www.mellowgold.com/grow/mjbotany-removed/marijuanabotany1.html Marijuana Botany Chapter 1 - Sinsemilla Life Cycle of Cannabis
/www.cannabisculture.com/articles/3127.html Need the dark
-------------------------------------------------------------
"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."
-------------------------------------------------------------
"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."
d.c. beard
Well-Known Member
lol the debate is over my ass
mafuki
Active Member
Your right its not over. I am just saying for me based off what i have found that its over until someone proves me wrong. I know people will always be divided on this issue but i thought i would share with you guys the details on why i came to this conclusion. I hope people read what i have wrote and do there own counter research to what i have found and get back to me.
bong hoger
Well-Known Member
crazy thread. but i would stil go for 18/6 its just more like in the wild. where in the wild does weed get 24/0 light for its veg stage.i have had 2 grow boxes one on 24/0 for its veg time and one box on 18/6 for its veg time both had same water and nutts. The plants on 18/6 had a avrige of 1lb 15oz and the 24/0 had a avrige of 1lb 2oz. Same strain!
Dr. Indica
Active Member
Hours of light and kelvin temperatures of lights have nothing to do with the sex of a plant. Chromosomes are responsible for determining sex. Otherwise you wouldn't have feminized seeds.
XX - female
XY - male
Hermie's are caused by
A. Bad Genetics from poor selective breeding
B. The Grower
C. Over Ripening
mafuki
Active Member
Thats cool that you did that experiment and the results are interesting. I have also read from many other forums where growers performed the same experiment and found the opposite results. People a lot of the times say that its more natural for it to have dark time but Scientists are finding out just how addaptive C3 plants are to light changes especially hybrid starins that have been bred indoors for many generation. Also is Hydroponics natural? is growing your cannabis under a light source which isnt the sun natural? I mean we have plants with 25% thc which was unheard of in the 60's.
mafuki
Active Member
LOL well Zebra im glad this thread helped you out in some small way
mr. green thumb 01
New Member
24 hours of light IMO bend the course of nature to get the most out of your controlled environment. More light more air more water more nutes more often=more everything=more=more=more= mc2...lol just not to much of one or the other. If your worried about stress then gradually drop light time to 12/12 not suddenly... O and for the poster about no 24 hr of light in the world is false...alaska has places that get 6months light straight. Dont replicate mother nature...improve it! If you wanted it to be just like mother nature intended it then no nutes...use only dirt, let it get watered by only rain and of course let it get nice and seedy just like mother nature intended....DUH!!!
IAm5toned
Well-Known Member
ive groewn both 18/6 and 24/0 and 20/4
ive grown the same strain side by side, one 18/6, one 24/0.
i got the best results vegging 24/0. best stem development, shortest internode spacing, and much more sturdy and vibrant growth, using 400w MH.
the only 'problem' i had with 24/0 was the constant trimming of older fan leaves so new growth could get better light quality...lol
so now, since i have figured out what my strain reacts better to (key phrase in that statement was 'my strain' its not MY strain, i didnt create it, it is an indica pakistani/afghani landrace cross stabilized by a hillbilly locally. he's back crossed it i dunnno how many times to get it stable. hes worked with it for over 20 yrs that i know of) i will veg moms under 24/0 clone under 24/0, last week of cloning (after theve rooted) i switch to 18/6, then 12/12 in the SOG....
ive grown the same strain side by side, one 18/6, one 24/0.
i got the best results vegging 24/0. best stem development, shortest internode spacing, and much more sturdy and vibrant growth, using 400w MH.
the only 'problem' i had with 24/0 was the constant trimming of older fan leaves so new growth could get better light quality...lol
so now, since i have figured out what my strain reacts better to (key phrase in that statement was 'my strain' its not MY strain, i didnt create it, it is an indica pakistani/afghani landrace cross stabilized by a hillbilly locally. he's back crossed it i dunnno how many times to get it stable. hes worked with it for over 20 yrs that i know of) i will veg moms under 24/0 clone under 24/0, last week of cloning (after theve rooted) i switch to 18/6, then 12/12 in the SOG....
mafuki
Active Member
Exactly, if you increase the light you need to increase everything else but just keep it balanced.
and Iam5toned, great avatar by the way
Jsmoke1989
Member
Its true you will save money on electricity but what you said about the ballast is untrue the last longer if they are never turned off as do the bulbs, in terms of hours anyways the bulb would probably fail sooner than it would otherwise but with more hours of use on it. the reason being is the stress that is put on the internal components transformer, cap, and/or ignitor from the surge of energy rushing into them every time they are turned on instead of a nice steady stream that the parts are made to continuously handle. Although if the conditions were far too hot and it wasnt being kept cool it wouldnt really matter. I am an electrician and know this to be fact i'm not trying to rag on you just trying to clarify a little and make sure people get the right info. I do agree with what the others said though to each his own just tryin to make sure the facts are straight.
DannyGreenEyes
Well-Known Member
Hi everyone, I'm what you might called an advanced newbie on his first grow and I though I'd just throw in my 2 cents.
Let me first say that I did a lot of research along the way including reading many published scientific studies about increasing the potency of MJ. There are several growing techniques that I've heard of, and a few seem very viable. One I even read about in some of those scientific studies that I mentioned. However, a plant grown normally can only contain 20% THC, it's in the genetics. Again, you can enhance this through growing techniques that force Tricombe development and resin production. But a standard plant grown under normal conditions can only contain 20% max.
The only way around this is to make yourself a Polyploidy which is not an easy task. But when you do this you double the number of chromosomes. The only way a plant can do something beyond it's genetic capabilities is to change the genetics.
I heard the arguments on light scedules both ways before I started and I decided to go with 24/0 because I figured the more light, the more photsynthesis, the more growth. And I'm sorry that I did.
I have nice plants at nine weeks don't get me wrong, and for all the problems that I have faced it's actually pretty surprising that I have 2' plants at 9 weeks. But a large part of that was the Mycorrhiza that I discovered. If anyone wants bigger roots that are better colonized and are capable of absorbing more of everything, get to a nursery & pick yourself up some MYKEs Tree & Shrub Transplanter. There are other species of Mycorrhiza, and I've heard good and bad about all of them. But MYKEs is the only one I have experience with, and I just had to transfer my plants into 10 gal. containers because the roots needed more room.
There are a few reasons why I'm sorry I went with 24/0...............
1 - I can't do any foliar feeding. I'd be able to get my girls more water & nutes if I could. Only a small percentage more, but more is more.
2 - I live in a dry state and as a result mites are always a concern. I made it through a triple infestation (Spider Mites, Broad Mites, & Fungus Gnats) with the help of some Lady Bugs. IMO they are the best things to use as a first line of defense. But they hunt in the dark, so they'd be more beneficial with a dark period. Also, it would help me to keep them on the plants if I could spray the plants. If they knew they'd be getting their water on the leaves, it would help to keep them on the plants. I could even spray them with sweet water to keep them from flying so they wouldn't keep frying themselves on the HIDs.
3 - When I spray for bugs I have to take them out of the room so they don't get burned by the lights. The room is just too small. Plus I have to take them out once a week to clean up the dead lady bugs. If they had a dark period I'd be able to do it during the dark period since all I have outside the room is regular light bulbs I'm sure they consider this a dark period that they get once a week. I'm sure this isn't good for them, but I have no choice.
I'll be putting them into flower as soon as I treat one or two more times to make sure the Broad Mites are finished, so by next weekend they'll be on 12/12. I'm setting up a different room for veg now and I'll be setting it up for either 20/4 or 22/2 just so I can get as much light as possible while having the dark time to take care of the problems that I mentioned above.
So in short, the foliar feeding & any bug problems that may come up make a 2 or 4 hr. dark period a lot smarter in my opinion.
Thanks for the info on slowly changing the light schedule to get them into flower. I never thought of it. +rep
Let me first say that I did a lot of research along the way including reading many published scientific studies about increasing the potency of MJ. There are several growing techniques that I've heard of, and a few seem very viable. One I even read about in some of those scientific studies that I mentioned. However, a plant grown normally can only contain 20% THC, it's in the genetics. Again, you can enhance this through growing techniques that force Tricombe development and resin production. But a standard plant grown under normal conditions can only contain 20% max.
The only way around this is to make yourself a Polyploidy which is not an easy task. But when you do this you double the number of chromosomes. The only way a plant can do something beyond it's genetic capabilities is to change the genetics.
I heard the arguments on light scedules both ways before I started and I decided to go with 24/0 because I figured the more light, the more photsynthesis, the more growth. And I'm sorry that I did.
I have nice plants at nine weeks don't get me wrong, and for all the problems that I have faced it's actually pretty surprising that I have 2' plants at 9 weeks. But a large part of that was the Mycorrhiza that I discovered. If anyone wants bigger roots that are better colonized and are capable of absorbing more of everything, get to a nursery & pick yourself up some MYKEs Tree & Shrub Transplanter. There are other species of Mycorrhiza, and I've heard good and bad about all of them. But MYKEs is the only one I have experience with, and I just had to transfer my plants into 10 gal. containers because the roots needed more room.
There are a few reasons why I'm sorry I went with 24/0...............
1 - I can't do any foliar feeding. I'd be able to get my girls more water & nutes if I could. Only a small percentage more, but more is more.
2 - I live in a dry state and as a result mites are always a concern. I made it through a triple infestation (Spider Mites, Broad Mites, & Fungus Gnats) with the help of some Lady Bugs. IMO they are the best things to use as a first line of defense. But they hunt in the dark, so they'd be more beneficial with a dark period. Also, it would help me to keep them on the plants if I could spray the plants. If they knew they'd be getting their water on the leaves, it would help to keep them on the plants. I could even spray them with sweet water to keep them from flying so they wouldn't keep frying themselves on the HIDs.
3 - When I spray for bugs I have to take them out of the room so they don't get burned by the lights. The room is just too small. Plus I have to take them out once a week to clean up the dead lady bugs. If they had a dark period I'd be able to do it during the dark period since all I have outside the room is regular light bulbs I'm sure they consider this a dark period that they get once a week. I'm sure this isn't good for them, but I have no choice.
I'll be putting them into flower as soon as I treat one or two more times to make sure the Broad Mites are finished, so by next weekend they'll be on 12/12. I'm setting up a different room for veg now and I'll be setting it up for either 20/4 or 22/2 just so I can get as much light as possible while having the dark time to take care of the problems that I mentioned above.
So in short, the foliar feeding & any bug problems that may come up make a 2 or 4 hr. dark period a lot smarter in my opinion.
Thanks for the info on slowly changing the light schedule to get them into flower. I never thought of it. +rep
IAm5toned
Well-Known Member
high bay fixtures (some growers call em chrome domes or mr cleans) are especially suited for 24/0 operation
DaveCoulier
Well-Known Member
Danny, it is perfectly fine to foliar feed with lights on. Ive done it by raising the lights a couple of feet with no burns. Then I did it a couple of times and I forgot to raise the lights, and once again no burns.
A droplet of water on a smooth leaf shouldn't cause burning, but if the water droplets are suspended on fine hairs that some plants have it can/will cause burns because there is space for the light to be focused.
Think about how as a kid you'd take a magnifying glass and burn insects or paper or what not. You couldn't just put it right on top of the item. You'd have to find the right focal point by raising the lens up or down.
You can google it and there is a experiment or two that tackled this myth.
The biggest reason people get burns from foliar feeding with lights on isn't because of the lights, its because they used too much ferts in their foliar feed. Ive done this once before. Also as the water evaporates, it can leave behind excess salt/ fertilizer crystals that will burn the leaves.
Heres a link that you might enjoy reading.
http://www.puyallup.wsu.edu/~Linda Chalker-Scott/Horticultural Myths_files/Myths/Leaf scorch.pdf
DannyGreenEyes
Well-Known Member
Thanks for the link. +rep
But for now I won't be spraying with the lights on. I tried it when I first got the lady bugs with my lights hung at around 28". Just plain pH'd water and my girls got burned. Then it happened again...... I was spraying the mylar with plain water to give the Lady Bugs a drink and I guess some dribbled down the mylar and onto some leaves that were touching it. More burns.
And I can't raise my lights much more than they are now. I think I'm gonna have to get some hooks with anchors so I can hang them from the ceiling. They're hanging from a 2x4 about a ft below the ceiling now. But my girls are getting tall and the 10 gallon contaiers are a few inches taller than the 5 gallon. If they triple in size during flower (and I think they might do better than that thanks to the roots) there's not going to be a whole lot of room between the girls & the lights by the time I get them to harvest.
Thanks again for the link though. I'm always looking to learn. And if it's possible to spray them with the lights on, I might give it another try. But at this point, with my prior experience with it, I don't see it happening.