Bloom timing and incremental light depravation.

Wassssuuuuuuuuupppp!

So, my first marijuana grow was generally based on alot of information that I gathered online that I picked through with a fine toothed try comb... A lot of it was anecdotal. When I switched to "bloom" I went by instinct. Basically, plant size and health.
I just switched the light to "Bloom", changed the timer to 12/12, and let er rip. Didn't seem to affect anything but I have not tested yet.
I've seen some articles that suggest changing the timing incrementally and gradually dropping "sun" time like the way the season change would. A little at a time.
Has anyone compared the results of doing this? I imagine there's some shock to the plant just switching from 18/6 to 12/12 but that might be a good thing to get the plant moving into flowering quicker. OR, it could have a negative effect and actually cause the plants buds to be stunted and smaller and maybe not as many as you could have.
 

Bukvičák

Well-Known Member
Wassssuuuuuuuuupppp!

So, my first marijuana grow was generally based on alot of information that I gathered online that I picked through with a fine toothed try comb... A lot of it was anecdotal. When I switched to "bloom" I went by instinct. Basically, plant size and health.
I just switched the light to "Bloom", changed the timer to 12/12, and let er rip. Didn't seem to affect anything but I have not tested yet.
I've seen some articles that suggest changing the timing incrementally and gradually dropping "sun" time like the way the season change would. A little at a time.
Has anyone compared the results of doing this? I imagine there's some shock to the plant just switching from 18/6 to 12/12 but that might be a good thing to get the plant moving into flowering quicker. OR, it could have a negative effect and actually cause the plants buds to be stunted and smaller and maybe not as many as you could have.
There are few things I have noticed… going from 24 to 12 takes longer time for flower to onset than 18 to 12, going from 18 lower intensity light like cfl to 12 high intensity HPS takes longer time than 18 to 12 under HPS. DLI drop is the thing which makes the magic happens. There is no benefit from prolonged darkness neither before nor after flowering. This actually has no scientific backup, including environmental changes and different seeds in my case. I tried, did not notice any benefit and 18 flip to 12 seems to be the best way so I stick with that…
 

Richard Drysift

Well-Known Member
I have experimented with light manipulation for many years and find it to be a great way to reduce stretching and sex out your plants. The sun does not have just 2 light cycles; the cycles change throughout the seasons as the earth revolves. Some strains can get downright lanky when forced right into flowering but gradually reducing the hours of daylight as it happens naturally outdoors can help reduce the amount of bare spaces in between nodes. Tight nodal stacking forms big ass bud later on. Problems is with big buds you can end up with other issues like mold. This is why I’ve stopped “monster cropping” plants because if done in combination with gradual light reduction you can grow enormously huge buds that harbor mold even with optimal conditions.
I like using this method to sex out plants: I veg as normal at 18/6 until about week 7. Then reduce the hours of light on my timer by an hour or 2 per week. From 18/6 to 17/8 and so on, etc. The more gradually you do it the more effect it has on the plants. Once they get down to around 14/10 most strains will begin throwing pistils; plants at this point are in both veg and bloom mode at the same time. Then you can identify the boys/girls and decide what to do from there…kill them, put them into 12/12 for bloom as they are, or go back into veg to bring them to desired size.
 

Bukvičák

Well-Known Member
I have experimented with light manipulation for many years and find it to be a great way to reduce stretching and sex out your plants. The sun does not have just 2 light cycles; the cycles change throughout the seasons as the earth revolves. Some strains can get downright lanky when forced right into flowering but gradually reducing the hours of daylight as it happens naturally outdoors can help reduce the amount of bare spaces in between nodes. Tight nodal stacking forms big ass bud later on. Problems is with big buds you can end up with other issues like mold. This is why I’ve stopped “monster cropping” plants because if done in combination with gradual light reduction you can grow enormously huge buds that harbor mold even with optimal conditions.
I like using this method to sex out plants: I veg as normal at 18/6 until about week 7. Then reduce the hours of light on my timer by an hour or 2 per week. From 18/6 to 17/8 and so on, etc. The more gradually you do it the more effect it has on the plants. Once they get down to around 14/10 most strains will begin throwing pistils; plants at this point are in both veg and bloom mode at the same time. Then you can identify the boys/girls and decide what to do from there…kill them, put them into 12/12 for bloom as they are, or go back into veg to bring them to desired size.
Veg and bloom mode at the same time? Like how?
 

simpleleaf

Well-Known Member
I have experimented with light manipulation for many years and find it to be a great way to reduce stretching and sex out your plants. The sun does not have just 2 light cycles; the cycles change throughout the seasons as the earth revolves. Some strains can get downright lanky when forced right into flowering but gradually reducing the hours of daylight as it happens naturally outdoors can help reduce the amount of bare spaces in between nodes. Tight nodal stacking forms big ass bud later on. Problems is with big buds you can end up with other issues like mold. This is why I’ve stopped “monster cropping” plants because if done in combination with gradual light reduction you can grow enormously huge buds that harbor mold even with optimal conditions.
I like using this method to sex out plants: I veg as normal at 18/6 until about week 7. Then reduce the hours of light on my timer by an hour or 2 per week. From 18/6 to 17/8 and so on, etc. The more gradually you do it the more effect it has on the plants. Once they get down to around 14/10 most strains will begin throwing pistils; plants at this point are in both veg and bloom mode at the same time. Then you can identify the boys/girls and decide what to do from there…kill them, put them into 12/12 for bloom as they are, or go back into veg to bring them to desired size.
Veg and bloom mode at the same time? Like how?
My green crack is showing pistils on 24/0, so I guess it's also in veg and bloom at the same time, although not as many as if it had been at 14/10 for a week or two. It's a clone that goes back a few cuttings. I guess it's older. :lol:

More seriously, there does appear to be a shock when changing from veg to bloom. It seems nothing changes for about a week. It is tedious to change the timer incrementally, without sufficient benefit. When do you start counting the days of bloom? The plant adjusts itself to new conditions quickly. If you increase darkness in 2-hour increments once a week, that means 6/18, 8/16, 10/14, that's 2 or 3 weeks. A plant going from 6/18 to 10/14 may not grow flowers the next day, but they'll be obvious in a week or two. So what's the difference?
 

hotrodharley

Well-Known Member
Wassssuuuuuuuuupppp!

So, my first marijuana grow was generally based on alot of information that I gathered online that I picked through with a fine toothed try comb... A lot of it was anecdotal. When I switched to "bloom" I went by instinct. Basically, plant size and health.
I just switched the light to "Bloom", changed the timer to 12/12, and let er rip. Didn't seem to affect anything but I have not tested yet.
I've seen some articles that suggest changing the timing incrementally and gradually dropping "sun" time like the way the season change would. A little at a time.
Has anyone compared the results of doing this? I imagine there's some shock to the plant just switching from 18/6 to 12/12 but that might be a good thing to get the plant moving into flowering quicker. OR, it could have a negative effect and actually cause the plants buds to be stunted and smaller and maybe not as many as you could have.
Leave both switches on the entire grow.
 

PadawanWarrior

Well-Known Member
I have experimented with light manipulation for many years and find it to be a great way to reduce stretching and sex out your plants. The sun does not have just 2 light cycles; the cycles change throughout the seasons as the earth revolves. Some strains can get downright lanky when forced right into flowering but gradually reducing the hours of daylight as it happens naturally outdoors can help reduce the amount of bare spaces in between nodes. Tight nodal stacking forms big ass bud later on. Problems is with big buds you can end up with other issues like mold. This is why I’ve stopped “monster cropping” plants because if done in combination with gradual light reduction you can grow enormously huge buds that harbor mold even with optimal conditions.
I like using this method to sex out plants: I veg as normal at 18/6 until about week 7. Then reduce the hours of light on my timer by an hour or 2 per week. From 18/6 to 17/8 and so on, etc. The more gradually you do it the more effect it has on the plants. Once they get down to around 14/10 most strains will begin throwing pistils; plants at this point are in both veg and bloom mode at the same time. Then you can identify the boys/girls and decide what to do from there…kill them, put them into 12/12 for bloom as they are, or go back into veg to bring them to desired size.
Good info as always. Do they reveg if you switch back to veg?
 

PadawanWarrior

Well-Known Member
My green crack is showing pistils on 24/0, so I guess it's also in veg and bloom at the same time, although not as many as if it had been at 14/10 for a week or two. It's a clone that goes back a few cuttings. I guess it's older. :lol:

More seriously, there does appear to be a shock when changing from veg to bloom. It seems nothing changes for about a week. It is tedious to change the timer incrementally, without sufficient benefit. When do you start counting the days of bloom? The plant adjusts itself to new conditions quickly. If you increase darkness in 2-hour increments once a week, that means 6/18, 8/16, 10/14, that's 2 or 3 weeks. A plant going from 6/18 to 10/14 may not grow flowers the next day, but they'll be obvious in a week or two. So what's the difference?
If a plant is mature they'll have tiny pistils on the stem, even if they're clones. Totally normal. Where'd you get the clones?
 

simpleleaf

Well-Known Member
If a plant is mature they'll have tiny pistils on the stem, even if they're clones. Totally normal. Where'd you get the clones?
"Mature" means they're older. :lol: Most likely Seedsman, the seed was from Garden of Green, I've cloned it for several blooms. I grew 2 seeds, 1 was hermie, so I cloned the other. I don't have a good camera for closeups, otherwise I'd snap a pic.
 
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I have experimented with light manipulation for many years and find it to be a great way to reduce stretching and sex out your plants. The sun does not have just 2 light cycles; the cycles change throughout the seasons as the earth revolves. Some strains can get downright lanky when forced right into flowering but gradually reducing the hours of daylight as it happens naturally outdoors can help reduce the amount of bare spaces in between nodes. Tight nodal stacking forms big ass bud later on. Problems is with big buds you can end up with other issues like mold. This is why I’ve stopped “monster cropping” plants because if done in combination with gradual light reduction you can grow enormously huge buds that harbor mold even with optimal conditions.
I like using this method to sex out plants: I veg as normal at 18/6 until about week 7. Then reduce the hours of light on my timer by an hour or 2 per week. From 18/6 to 17/8 and so on, etc. The more gradually you do it the more effect it has on the plants. Once they get down to around 14/10 most strains will begin throwing pistils; plants at this point are in both veg and bloom mode at the same time. Then you can identify the boys/girls and decide what to do from there…kill them, put them into 12/12 for bloom as they are, or go back into veg to bring them to desired size.
If it has 2 switches I don't care what's under it. Standard advice here is leave both on. But people do as they want.
Makes the tent too hot. I thought about it and is it really needed? Will the plant grow more in less time? Does it mature faster? Will it be ready to flower in 4 weeks instead of 8?
I switched this to bloom yesterday. It's about 9 weeks old. If I used both lights, would it look like this in half the time?
 

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Bignutes

Well-Known Member
I agree, I start my flower at 13.5 hours for first 10 days, then 13 for the next 10 days and drop it eventually to 11.5 hours. Most strains will flower at 13.5 hours with no delay on schedule. My plants also get sunrise and sunset.
 

hotrodharley

Well-Known Member
Makes the tent too hot. I thought about it and is it really needed? Will the plant grow more in less time? Does it mature faster? Will it be ready to flower in 4 weeks instead of 8?
I switched this to bloom yesterday. It's about 9 weeks old. If I used both lights, would it look like this in half the time?
Photosynthesis. That light is not going to overpower. Can you get some air flow going? It won't mature faster but I'll promise it will weigh more.
 

Richard Drysift

Well-Known Member
My green crack is showing pistils on 24/0, so I guess it's also in veg and bloom at the same time, although not as many as if it had been at 14/10 for a week or two. It's a clone that goes back a few cuttings. I guess it's older. :lol:

More seriously, there does appear to be a shock when changing from veg to bloom. It seems nothing changes for about a week. It is tedious to change the timer incrementally, without sufficient benefit. When do you start counting the days of bloom? The plant adjusts itself to new conditions quickly. If you increase darkness in 2-hour increments once a week, that means 6/18, 8/16, 10/14, that's 2 or 3 weeks. A plant going from 6/18 to 10/14 may not grow flowers the next day, but they'll be obvious in a week or two. So what's the difference?
My green crack is showing pistils on 24/0, so I guess it's also in veg and bloom at the same time, although not as many as if it had been at 14/10 for a week or two. It's a clone that goes back a few cuttings. I guess it's older. :lol:

More seriously, there does appear to be a shock when changing from veg to bloom. It seems nothing changes for about a week. It is tedious to change the timer incrementally, without sufficient benefit. When do you start counting the days of bloom? The plant adjusts itself to new conditions quickly. If you increase darkness in 2-hour increments once a week, that means 6/18, 8/16, 10/14, that's 2 or 3 weeks. A plant going from 6/18 to 10/14 may not grow flowers the next day, but they'll be obvious in a week or two. So what's the difference?
Now I’m confused…
Always thought it was light/dark like 18/6 for a veg cycle but maybe it’s different in other places if the world… switching it around makes your Q more coherent for me….
I don’t count days anymore but I do keep track of how many full weeks they are in bloom. Even if they are showing pistils I don’t count that time as bloom time…I begin counting the weeks in bloom once they are forming pistils and under a 12/12 cycle. The transition time is not factored in at all and so you can pretty much plan on most strains finishing around 10-11 weeks.
 

simpleleaf

Well-Known Member
Now I’m confused…
Always thought it was light/dark like 18/6 for a veg cycle but maybe it’s different in other places if the world… switching it around makes your Q more coherent for me….
I don’t count days anymore but I do keep track of how many full weeks they are in bloom. Even if they are showing pistils I don’t count that time as bloom time…I begin counting the weeks in bloom once they are forming pistils and under a 12/12 cycle. The transition time is not factored in at all and so you can pretty much plan on most strains finishing around 10-11 weeks.
Sorry, there's a reason I switched to darkness hours! It's my understanding that the blooming hormone, florigen, builds up depending on contiguous nighttime hours, daytime hours are basically irrelevant, even though most of us think of photoperiod in terms of light hours. Once the florigen reaches a certain level, which is in turn dictated by hours of darkness, then the flowers start growing. If you interrupt the long dark hours with some light in the middle of the dark period, it will prevent flowering. I don't believe the delay in flowering is a shock due to changing photoperiod, rather just represents the time for flower hormone to accumulate to the level needed to trigger flower growth.

Here's an old RIU discussion that mentions some of it.


There are some science studies I've seen that mention it, but it's really deep reading, see page 2 of the following PDF.

 
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Photosynthesis. That light is not going to overpower. Can you get some air flow going? It won't mature faster but I'll promise it will weigh more.
Weight as in harvest weight or more flower bud sites? I'm just looking for personal consumption. If you look at my plants in the noob section, what would I have had (estimate) if I had run both lights? Because there was alot there and I don't need a ton. I'm still trying to find something, a strain, to cope with my Multiple Sclerosis.

Yeah, I have a fan inside and another outside blowing into one of the vent holes for fresh air. The grow tent is tucked in on the right side of my laundry room. I have a charcoal filter inside and there's a bathroom exhaust fan in that room for backup.
I bought the whole set-up with government stimulus money , and rigged it myself. FJB!
Maybe I'll run both lights next time. The only way I'll be sure for myself. I just don't want to waste time and kill a plant on re-pot into the tent. That would suck.
 

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Richard Drysift

Well-Known Member
Good info as always. Do they reveg if you switch back to veg?
Yes of course but there’s always like a week or so of transition. Adds a week+ every time you switch back and/or forth. Revegging after they have bloomed even for a short time makes for some monster size bud if you have lighting intense enough to penetrate a thick canopy and the vertical space to let them grow. But again growing big ass buds like this can also bring unwanted issues like mold into play of conditions are less than optimal.
 
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