Dr. Who
Well-Known Member
There are tests on light times that go down to 6 on 18 off......The plant actually flowers very quickly....These studies are based on a paper written in 1913 in France when Julien Turneux or Turnou growing "Hemp" and Hops Under glass (in a greenhouse) found that the plants flowered "vigorously" at reduced light times down to 6 hrs of light.
I would be more inclined to work around Uncle Ben's statement.....As long as your PAR lighting requirements of the plant are reached.....lower away! Beyond that point is where you loose..
Late in bloom on Sativa's that are not finishing or going too long..... Lowering the on time to 10 hrs will initiate the plant to finish.
HPS has far more PAR lighting then MH.....It's 50% more efficient (electrically speaking) then MH and can deliver the plants PAR requirements faster. This is another basis on shorter over the whole lighting times working....
Increasing to over 12/12 is simply a waste as you are then forcing the plant to have less light saturation recovery time. You see, the plant actually reduces the light exposure it gets during the day beginning quite early, say like mid to late mourning. The plant reaches a light "saturation" point where it is beginning to change on a cellular level to protect it's self from the intensity of the light.....The light is still producing photosynthesis in the plant but, at a reduced amount that progresses on a sort of bell curve. See, plants (ours) do not require a night to grow BUT, with out one. Recovery of the plant to be able to most effectively use the light is reduced and you get reduced root growth along with hormone imbalance's that don't act as a benefit!
If you have lots of money to spend on lighting. The manipulation of the pfr lighting (730 nm band deep red spectrum) by LEDs of 730 nm will reduce the plants 2 hr shift to "night time" down to minutes. The idea behind this is that you gain back those 2 hrs of the plant shift or lighting response time to only minutes and you can use this time for extended lights on time...I tried it and am not impressed with the gain to cost ratio....
I always bloom Indica's and mutts under 11/13 as I feel the plants genetic potential is easier to reach and causes less stress....Sativa's of an 80% or better nature...get 12/12 but that begins to lower on a short progressive sched. as they get deeper into bloom......Like this -
flip to 8 weeks = 12/12
8 to 10 weeks = 11.5/12.5
10 to 12 weeks = 11/13
12 to 14 weeks = 10.5/13.5
finish at 10/14
Some Landraces get less reduction by 50%
With lower lights on time, I have not had any problems with airy or loose buds as long as I keep the Co2 at a min of 1000ppm....Right on down to 8< lighting time......
Dark for 3 days does nothing effective or helpful.
Doc
I would be more inclined to work around Uncle Ben's statement.....As long as your PAR lighting requirements of the plant are reached.....lower away! Beyond that point is where you loose..
Late in bloom on Sativa's that are not finishing or going too long..... Lowering the on time to 10 hrs will initiate the plant to finish.
HPS has far more PAR lighting then MH.....It's 50% more efficient (electrically speaking) then MH and can deliver the plants PAR requirements faster. This is another basis on shorter over the whole lighting times working....
Increasing to over 12/12 is simply a waste as you are then forcing the plant to have less light saturation recovery time. You see, the plant actually reduces the light exposure it gets during the day beginning quite early, say like mid to late mourning. The plant reaches a light "saturation" point where it is beginning to change on a cellular level to protect it's self from the intensity of the light.....The light is still producing photosynthesis in the plant but, at a reduced amount that progresses on a sort of bell curve. See, plants (ours) do not require a night to grow BUT, with out one. Recovery of the plant to be able to most effectively use the light is reduced and you get reduced root growth along with hormone imbalance's that don't act as a benefit!
If you have lots of money to spend on lighting. The manipulation of the pfr lighting (730 nm band deep red spectrum) by LEDs of 730 nm will reduce the plants 2 hr shift to "night time" down to minutes. The idea behind this is that you gain back those 2 hrs of the plant shift or lighting response time to only minutes and you can use this time for extended lights on time...I tried it and am not impressed with the gain to cost ratio....
I always bloom Indica's and mutts under 11/13 as I feel the plants genetic potential is easier to reach and causes less stress....Sativa's of an 80% or better nature...get 12/12 but that begins to lower on a short progressive sched. as they get deeper into bloom......Like this -
flip to 8 weeks = 12/12
8 to 10 weeks = 11.5/12.5
10 to 12 weeks = 11/13
12 to 14 weeks = 10.5/13.5
finish at 10/14
Some Landraces get less reduction by 50%
With lower lights on time, I have not had any problems with airy or loose buds as long as I keep the Co2 at a min of 1000ppm....Right on down to 8< lighting time......
Dark for 3 days does nothing effective or helpful.
Doc
