SmithsJunk
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Sweet, thanks
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Sweet, thanks
SmithsJunk
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Good, clear info here about par and all.
https://www.thcfarmer.com/community...-for-humans-about-par-ppf-ppfd-and-dli.84822/
So this is the diagram for my CXB3590x2 (actually it's for the CXB3590x2II, it's the same fixture with some digital additions but the lighting components are the same)
My light is close to 8" away and it's footprint at this distance is 7.5'sq. My canopy is less than 6'sq (that this fixture is servicing) and the Mylar is 99% reflective (I wonder if that is 99% of PAR or all light, or if there is any difference in reflection between the two), so I should be getting most of 2500micro mols per second. So 2500 × 0.0864 = 216 (DLI), and since I'm running my lights 12hrs then my DLI at canopy height is around 108 moles, right? Seems like an aweful lot. Am I missing a calculation somewhere?
Am I at least on the right track here? Should I be dimming my lights by nearly 40% to be getting better photosynthesis? I can do that and was during veg. My single is already running at 67% of my double. Do I need CO2 generators at this rate or would that only be if they were indoor?
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SmithsJunk
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Grow Log 12/9/18
Thanks to @CrimsonEcho for pointing me to a very informative article on what PAR is. I had an excellent jump off point to gather enough information to understand the light my fixtures produce and what's necessary for the flower cycle. I've adjusted my light output accordingly, reducing it by 25% for better photosynthesis. (I think, hahaha. I'm not done studying.)
Thanks to @CrimsonEcho for pointing me to a very informative article on what PAR is. I had an excellent jump off point to gather enough information to understand the light my fixtures produce and what's necessary for the flower cycle. I've adjusted my light output accordingly, reducing it by 25% for better photosynthesis. (I think, hahaha. I'm not done studying.)
crimsonecho
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So this is the diagram for my CXB3590x2 (actually it's for the CXB3590x2II, it's the same fixture with some digital additions but the lighting components are the same)
View attachment 845977
My light is close to 8" away and it's footprint at this distance is 7.5'sq. My canopy is less than 6'sq and the Mylar is 99% reflective (I wonder if that is 99% of PAR or all light, or if there is any difference in reflection between the two), so I should be getting most of 2500micro mols per second. So 2500 × 0.0864 = 216 (DLI), and since I'm running my lights 12hrs then my DLI at canopy height is around 108 moles, right? Seems like an aweful lot. Am I missing a calculation somewhere?
Am I at least on the right track here. Should I be dimming my lights by nearly 40% to be getting better photosynthesis? I can do that and was during veg. My single is already running at 67% of my double. Do I need CO2 generators at this rate or would that only be if they were indoor?
Good question. Never delved into dli calculations and ppfd myself. But if that values are correct -by the way, these companies usually take direct readings under the cobs and serve it as the ppfd value, which doesn’t give the whole story- then your calculation seems right. But to get actual dli values you should have a quantum meter or a detailed ppfd chart. All in all i think you can dim it a bit. Maybe to 70%?
SmithsJunk
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Good question. Never delved into dli calculations and ppfd myself. But if that values are correct -by the way, these companies usually take direct readings under the cobs and serve it as the ppfd value, which doesn’t give the whole story- then your calculation seems right. But to get actual dli values you should have a quantum meter or a detailed ppfd chart. All in all i think you can dim it a bit. Maybe to 70%?
Hahaha, I just did to 75% because one of my girls is at around 11-12". Perfect man. Thank you so much. It's great when you begin to understand and aren't just guessing anymore.
crimsonecho
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This is a very confusing calculation because you are taking spot measurements but use m2/s. The sensors are tiny not m2 but cm2 :DHahaha, I just did to 75% because one of my girls is at around 11-12". Perfect man. Thank you so much. It's great when you begin to understand and aren't just guessing anymore.
I just can’t wrap my head around it too. If i had a meter i would take 10 different readings around 1m2 and take average and do the dli calculation so i could have a true average dli of my grow area.
This calculations are too advanced for me, i’m just sticking with spectrum, efficacy and maybe ppfd :D
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@jumpincactus can help tho i’m sure :) to both of us :D
SmithsJunk
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@jumpincactus can help tho i’m sure :) to both of us :D
No reason to get Jumpincactus involved yet. I'm just breaking through and am going to do a lot more studying. My brain is like, "Okay bud, that's enough from you today. Go get me a bowl now. I earned it." Hahaha.
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My brain is like, "Okay bud, that's enough from you today. Go get me a bowl now. I earned it." Hahaha.
I do the same thing haha!
jumpincactus
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Cactusman, lowers his head, puts hands in pockets and walks away feeling so neglected, abused and unloved...……. Nobody loves the Cactusman. lmfao. :(:cry: And thats fine Mr. Smith, :D when ya really need me I'll be in abandonment therapy and not able to help when you need me the most.:p LOLNo reason to get Jumpincactus involved yet. I'm just breaking through and am going to do a lot more studying. My brain is like, "Okay bud, that's enough from you today. Go get me a bowl now. I earned it." Hahaha.
crimsonecho
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Cactusman, lowers his head, puts hands in pockets and walks away feeling so neglected, abused and unloved...……. Nobody loves the Cactusman. lmfao. :(:cry: And thats fine Mr. Smith, :D when ya really need me I'll be in abandonment therapy and not able to help when you need me the most.:p LOL
Awww come on mr. cactus, we love ya :D
SmithsJunk
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Cactusman, lowers his head, puts hands in pockets and walks away feeling so neglected, abused and unloved...……. Nobody loves the Cactusman. lmfao. :(:cry: And thats fine Mr. Smith, :D when ya really need me I'll be in abandonment therapy and not able to help when you need me the most.:p LOL
ROFL
Oh, it's far from that Cactusman. I feel that your knowledge is so valuable that I want to understand enough to bring you solid questions and be able to fully understand your answers. I've just learned enough to be dangerous so far and I'm not ready for your very advanced answers. I need about a week to fully understand the science. Not that it will take me more than a few days but I have lots of trimming still to do because I've lined up some new outlets and I'm very behind.
I only asked Echo because he gave me the preliminary info, your thread. Thank you for that PAR explaination.
SmithsJunk
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Awww come on mr. cactus, we love ya :D
Absolutely.
4plant
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I found this write up,
For cannabis, bottom threshold for optimal growth and photosynthesis is a DLI of DLI of 22 would be:
****Going lower than these numbers will still grow cannabis, however yields, bud density, potency and THC percentage may suffer.
24/0 schedule: 254.6 micromoles/m2/s-1
18/6 schedule: 381.5 micromoles/m2/s-1
12/12 schedule: 509.25 micromoles/m2/s-1
For Cannabis, the Top threshold for optimal growth and photosynthesis is a DLI of 65 moles per day.
***extremely important notice, only go up to these amounts if you are using supplemental CO2, do not go this high if you are not using supplemental CO2 as you will actually slow down photosynthesis and waste energy.
24/0 schedule: 752.31 micromoles/m2/s-1
18/6 schedule: 1128.465 micromoles/m2/s-1
12/12 schedule: 1504.6 micromoles/m2/s-1
The generally accepted guidelines for artificial light PPFD in flowering are this:
in a 12/12
PPFD of at least 510 micromoles/m2/s-1 for the low end of optimal intensity
PPFD of at least 800-1100 micromoles/m2/s-1 for perfect optimal lighting without additional CO2.
PPFD of at least 800-1500 micromoles/m2/s-1 for perfect optimal lighting WITH additional CO2.
For cannabis, bottom threshold for optimal growth and photosynthesis is a DLI of DLI of 22 would be:
****Going lower than these numbers will still grow cannabis, however yields, bud density, potency and THC percentage may suffer.
24/0 schedule: 254.6 micromoles/m2/s-1
18/6 schedule: 381.5 micromoles/m2/s-1
12/12 schedule: 509.25 micromoles/m2/s-1
For Cannabis, the Top threshold for optimal growth and photosynthesis is a DLI of 65 moles per day.
***extremely important notice, only go up to these amounts if you are using supplemental CO2, do not go this high if you are not using supplemental CO2 as you will actually slow down photosynthesis and waste energy.
24/0 schedule: 752.31 micromoles/m2/s-1
18/6 schedule: 1128.465 micromoles/m2/s-1
12/12 schedule: 1504.6 micromoles/m2/s-1
The generally accepted guidelines for artificial light PPFD in flowering are this:
in a 12/12
PPFD of at least 510 micromoles/m2/s-1 for the low end of optimal intensity
PPFD of at least 800-1100 micromoles/m2/s-1 for perfect optimal lighting without additional CO2.
PPFD of at least 800-1500 micromoles/m2/s-1 for perfect optimal lighting WITH additional CO2.
SmithsJunk
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I found this write up,
For cannabis, bottom threshold for optimal growth and photosynthesis is a DLI of DLI of 22 would be:
****Going lower than these numbers will still grow cannabis, however yields, bud density, potency and THC percentage may suffer.
24/0 schedule: 254.6 micromoles/m2/s-1
18/6 schedule: 381.5 micromoles/m2/s-1
12/12 schedule: 509.25 micromoles/m2/s-1
For Cannabis, the Top threshold for optimal growth and photosynthesis is a DLI of 65 moles per day.
***extremely important notice, only go up to these amounts if you are using supplemental CO2, do not go this high if you are not using supplemental CO2 as you will actually slow down photosynthesis and waste energy.
24/0 schedule: 752.31 micromoles/m2/s-1
18/6 schedule: 1128.465 micromoles/m2/s-1
12/12 schedule: 1504.6 micromoles/m2/s-1
The generally accepted guidelines for artificial light PPFD in flowering are this:
in a 12/12
PPFD of at least 510 micromoles/m2/s-1 for the low end of optimal intensity
PPFD of at least 800-1100 micromoles/m2/s-1 for perfect optimal lighting without additional CO2.
PPFD of at least 800-1500 micromoles/m2/s-1 for perfect optimal lighting WITH additional CO2.
Great info, thanks.
I found something similar but the DLI was 66. One thing to consider is that I'm not running my tent indoors. It's getting outside air directly blown in. That may have been why I was able to get away with a DLI of over 108 (actually, probably closer to 140-150 since I was only talking about 2/3 of my lighting) but I'm sure it still slowed photosynthesis a great deal. They do look like they've picked up the growth rate since I lowered my x2 by 25%.
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SmithsJunk
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I've been really busy today so no pics. I'm hoping that when I bring the girls out to collect pollen tomorrow I'll get some good open pollen flower pics. The herm'd pollen flowers are quite pretty. They often have had a set of stigma coming directly out of their centers. It's cool looking.
SmithsJunk
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I don't think letting her go longer is going to help these flowers.
SmithsJunk
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Grow Log 12/11/18 (tent)
They really have taken off since I turned down the CXB3590x2. Thanks @CrimsonEcho & @jumpincactus for your tutelage.
I'll post up better pics when it gets warmer today and I can open the tent. Hopefully I get some freshly opened pollen flowers too.
They really have taken off since I turned down the CXB3590x2. Thanks @CrimsonEcho & @jumpincactus for your tutelage.
I'll post up better pics when it gets warmer today and I can open the tent. Hopefully I get some freshly opened pollen flowers too.
SmithsJunk
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Grow Log 12/11/18 (tent)
The girls are doing fantastic. I'm planning on adding a little Krazy Kelp to the next feeding. It looks like they're depleted. Doesn't matter how good the microbes work they still need something to work with. The girls are using a lot more water than when they were cold but the Sea Green had caused an increased uptake even before that. Increased watering gives more opportunity to feed them. I'm watering 4x more often than when they were still weak.
Nothing open yet but there are some that are close. The first three are fem and fem pollen in one bud. I bet if I left them on they'll seed.
This one is very close.
The girls are doing fantastic. I'm planning on adding a little Krazy Kelp to the next feeding. It looks like they're depleted. Doesn't matter how good the microbes work they still need something to work with. The girls are using a lot more water than when they were cold but the Sea Green had caused an increased uptake even before that. Increased watering gives more opportunity to feed them. I'm watering 4x more often than when they were still weak.
Nothing open yet but there are some that are close. The first three are fem and fem pollen in one bud. I bet if I left them on they'll seed.
This one is very close.
jumpincactus
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im looking back at this from yesterday and it is Clear I was friggn toasted. :D:smoking::fire::fire::fire: I love cannabisAwww come on mr. cactus, we love ya :D
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