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How much light does weed really need??

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  • Nov 22 2010 02:25 AM
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Posted 22 November 2010 - 02:25 AM

first when is flowering and vegitation??? is flowering first?? if so how do you know when your at veg?
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Posted 22 November 2010 - 02:27 AM

Oh wow. Read the stickies, your basic questions are pre-answered there.

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Posted 22 November 2010 - 02:28 AM

call it cannabis... 18-24 hours during veg, i like to keep it 24h 12 on 12 off during flower

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Posted 22 November 2010 - 02:43 AM

Oh wow. Read the stickies, your basic questions are pre-answered there.


k so vegitations first with 6500k? for 18/6 and it goes intill it becomes decently big
then its lowerd to 2700k for 12/12 am i right??

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Posted 22 November 2010 - 08:34 AM

All these factors depend on how many plants you are growing, how close the lights are to the plants, and various other things. For a general rule of thumb their is a set per square food wattage or lumon chart, but like its been said already, its been posted time and time again here in the stickies.
You are correct to think that flowering occurs when a strict 12-12 time is kept. Veg is most commonly done on 24-0, then 18-6, some people then go to 16-8, but i find going to 12-12 right after 18-6 works great for most strains.

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Posted 22 November 2010 - 10:15 AM

k so vegitations first with 6500k? for 18/6 and it goes intill it becomes decently big
then its lowerd to 2700k for 12/12 am i right??

no all that crap is bulll
for veg you can use either one of those on a cfl
but
if you wanna grow some real buds get a hps light no questions asked
also you can use a hps the whole way through i alwayas have always will

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Posted 22 November 2010 - 01:56 PM

^Actually, that "crap" is correct.

The plant starts by vegging -- this is the stage of vegetative growth where the plant gets bigger and becomes ready for sexual maturation. Since MJ is an annual plant (grows from seed each Spring and dies each Fall/Winter), the veg stage takes place during late Spring and into early Summer, when days are long and the sun is more overhead, creating a more blue-light spectrum. To mimic this, you run long light periods (18 hours per day, up to a full 24 hours per day), and while using other light spectra can work, the spectrum that maximizes vegetative growth is 6500k.

The plant naturally goes into flowering mode as a hormonal reaction to the changing in light conditions as it gets into late Summer -- shorter days, and the sun moving to lower on the horizon means it filters through more atmosphere and shifts to a more red-spectrum light. For an indoor grow we trigger this hormonal reaction by switching the lights to 12 hours of light per day (and 12 hours uninterrupted dark) and shifting to light in the 2700k spectrum. You can flip to 12/12 any time you want.

And to the OP's original question, MJ is a sun-loving plant, so it wants lots of light.

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Posted 22 November 2010 - 07:24 PM

^Actually, that "crap" is correct.

The plant starts by vegging -- this is the stage of vegetative growth where the plant gets bigger and becomes ready for sexual maturation. Since MJ is an annual plant (grows from seed each Spring and dies each Fall/Winter), the veg stage takes place during late Spring and into early Summer, when days are long and the sun is more overhead, creating a more blue-light spectrum. To mimic this, you run long light periods (18 hours per day, up to a full 24 hours per day), and while using other light spectra can work, the spectrum that maximizes vegetative growth is 6500k.

The plant naturally goes into flowering mode as a hormonal reaction to the changing in light conditions as it gets into late Summer -- shorter days, and the sun moving to lower on the horizon means it filters through more atmosphere and shifts to a more red-spectrum light. For an indoor grow we trigger this hormonal reaction by switching the lights to 12 hours of light per day (and 12 hours uninterrupted dark) and shifting to light in the 2700k spectrum. You can flip to 12/12 any time you want.

And to the OP's original question, MJ is a sun-loving plant, so it wants lots of light.

so i was right??? with the timing and the k's?? if so will 3000k work in stead of 2700k?

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Posted 22 November 2010 - 07:30 PM

I think what Texas was saying is that you don't have to use 18/6 for veg, and it's true that 18/6 is one of several lighting plans that work well for veg. And that you don't have to use 6500k for veg, again it's true that 2700k will work, and some growers have only one spectrum for their lights at 2700k (because you really do want that spectrum for flowering), but you will veg better with 6500k.

3000k should be OK for flowering, but look around for 2700k they aren't hard to find.

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Posted 22 November 2010 - 09:28 PM

I think what Texas was saying is that you don't have to use 18/6 for veg, and it's true that 18/6 is one of several lighting plans that work well for veg. And that you don't have to use 6500k for veg, again it's true that 2700k will work, and some growers have only one spectrum for their lights at 2700k (because you really do want that spectrum for flowering), but you will veg better with 6500k.

3000k should be OK for flowering, but look around for 2700k they aren't hard to find.

oh so i could just use 3000k for the whole thing??

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Posted 22 November 2010 - 10:55 PM

Yes you can use flower spectrum for vegging, but it is not the best way to go.

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Posted 22 November 2010 - 10:56 PM

Yes you can use flower spectrum for vegging, but it is not the best way to go.

i under stand but will i get buds and if so how much gs ?

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Posted 23 November 2010 - 03:11 AM

Yes you'll get buds -- you're asking about veg lighting not flower lighting anyway.

No way to predict yield, way too many variables.


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