4x4 light for $1,000

UpstateRecGrower

Well-Known Member
Which is why I am trying to research and ask questions to get this right before a purchase. Do you know what the correct ppfd plants will peak at without any co2 added onto the grow?
I don't believe there is any magic number, but I wouldn't bother with much over 1000. Another thing to consider is that only the very tops will be getting that high par, anything below a top cola will be significantly lower.
 

JonCreighton

Active Member
lighting information is best taken from doc bruce bugbee from utah state... hes got some good papers on LED vs HID... hes also quite possible the leading plant scientis in the country and the guy who NASA turn to when they need to figure out how to grow plants in space.. there is some videos on youtube and you can find some other informatiuon from jsut searching google.

this is from mammoth lights website but they are basically paroting bugbees research...

Bottom threshold for optimal growth and photosynthesis is a DLI of 22:
24/0 schedule: 254.6 micromoles/m2/s-1
18/6 schedule: 339.5 micromoles/m2/s-1
12/12 schedule: 509.25 micromoles/m2/s-1

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: 1003.08 micromoles/m2/s-1
12/12 schedule: 1504.6 micromoles/m2/s-1

The generally accepted guidelines for artificial light PPFD in flowering during 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 optimal lighting WITHOUT additional CO2.
PPFD of at least 800-1500 micromoles/m2/s-1 for optimal lighting WITH additional CO2.


hope that helps
 

kovidkough

Well-Known Member
lighting information is best taken from doc bruce bugbee from utah state... hes got some good papers on LED vs HID... hes also quite possible the leading plant scientis in the country and the guy who NASA turn to when they need to figure out how to grow plants in space.. there is some videos on youtube and you can find some other informatiuon from jsut searching google.

this is from mammoth lights website but they are basically paroting bugbees research...

Bottom threshold for optimal growth and photosynthesis is a DLI of 22:
24/0 schedule: 254.6 micromoles/m2/s-1
18/6 schedule: 339.5 micromoles/m2/s-1
12/12 schedule: 509.25 micromoles/m2/s-1

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: 1003.08 micromoles/m2/s-1
12/12 schedule: 1504.6 micromoles/m2/s-1

The generally accepted guidelines for artificial light PPFD in flowering during 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 optimal lighting WITHOUT additional CO2.
PPFD of at least 800-1500 micromoles/m2/s-1 for optimal lighting WITH additional CO2.


hope that helps
I linked his videos somewhere on here
 

KoBo77

Member
lighting information is best taken from doc bruce bugbee from utah state... hes got some good papers on LED vs HID... hes also quite possible the leading plant scientis in the country and the guy who NASA turn to when they need to figure out how to grow plants in space.. there is some videos on youtube and you can find some other informatiuon from jsut searching google.

this is from mammoth lights website but they are basically paroting bugbees research...

Bottom threshold for optimal growth and photosynthesis is a DLI of 22:
24/0 schedule: 254.6 micromoles/m2/s-1
18/6 schedule: 339.5 micromoles/m2/s-1
12/12 schedule: 509.25 micromoles/m2/s-1

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: 1003.08 micromoles/m2/s-1
12/12 schedule: 1504.6 micromoles/m2/s-1

The generally accepted guidelines for artificial light PPFD in flowering during 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 optimal lighting WITHOUT additional CO2.
PPFD of at least 800-1500 micromoles/m2/s-1 for optimal lighting WITH additional CO2.


hope that helps
Hell yeah man! Thanks for this post, great info and I think I enjoy these topics too much...
 

Patriots781

Active Member
I ran a couple runs of autos on 18 6 12 inches away from a 1000 watt hps whondering why my leaves were falling off and then the next run there fine so if you run autos under 18 6 you should have a max ppfd of about 500 to 600 correct?m because the extra 6 hours??
 

UpstateRecGrower

Well-Known Member
I ran a couple runs of autos on 18 6 12 inches away from a 1000 watt hps whondering why my leaves were falling off and then the next run there fine so if you run autos under 18 6 you should have a max ppfd of about 500 to 600 correct?m because the extra 6 hours??
Yeah you won’t be able to use as strong of lights as if you were running a 12/12 cycle because you’re daylight interval is beyond what the plants can take.
 

Patriots781

Active Member
It's weird also cause most places outdoors have more light and stronger light in the veg stage months spring and summer and less in flower outside but inside they tell you to give less strong light in veg and strong light in flower backwards so if you grew autos outside you'd get bigger yields and you can get 2 harvests idk why more people dont go with autos maybe becausr they used to be smaller but lately ive seen some huge autos and personally grew s super lemon haze auto inside it grew until 4 feet in less then 2 months I have had better yields as well but what do I know I'm just a newbie
 

JonCreighton

Active Member
Here is another article and link that has good info that further backs this. Not implying anything just sharing a good read. https://www.cocoforcannabis.com/how-much-light-ppf-do-you-need-for-indoor-cannabis/
the chandra studies are great but i think bugbees stuff is a little more updated.... and the dude seems rock solid.. he seems to think most stuff can be pushed harder than chandra. photons (light intensity) is going to dictate ur yield for the most part but its worht noting this stuff isnt linear... its operates on abell curve where the most efficnet point is less than the maximum point... cannabis being a high value crop most people are pushing out as much yield as possible.. but this is a high risk strategy.. this might not be the best strategy for the home grower.. u need to have most of ur other factors optimnised to be pushing that hard and thats difficult to do... so i would say stay on the more efficent side of the bell curve numbers and dont worry as much about the max u can push them...
 

JonCreighton

Active Member
on a personal note im less woriied about how hard i can push them and more worried about the amount of light they are recieving throghout the stages... so i want to be at about 2/3 DLI switching to flower and get to 3/3 by week 4 of flower and let them ride form there... if i can only get them to 800ppfd by the time i flip to flower ill only run the lights up to 1200ppfd and not 1500ppfd even though i could...
 

UpstateRecGrower

Well-Known Member
on a personal note im less woriied about how hard i can push them and more worried about the amount of light they are recieving throghout the stages... so i want to be at about 2/3 DLI switching to flower and get to 3/3 by week 4 of flower and let them ride form there... if i can only get them to 800ppfd by the time i flip to flower ill only run the lights up to 1200ppfd and not 1500ppfd even though i could...
They won’t be able to take 1500, you’ll end up with low quality fluffy stuff. 1200 is even pushing it, aim for a 1000 max..
 

Patriots781

Active Member
I got a 630watt cmh for my other tent and I swear I compared with a light meter and my 780 watt enlite puts off at 20 percent 200 watts the same light at 43 inches as this new 630 watt cmh how is that even possible? Also I found a new led with cmh spectrum for veg and hps 2700k for bloom it looks pretty cool actually
 

SSHZ

Well-Known Member
If you have good air flow and negative pressure in the room, co2 becomes less important and extremely high yields are still possible. I'm at 2.3 GPW with the Gavita 1700e in a 4 x 4 space and wouldn't buy any other light. Make sure whatever you get is water proof, has a 5 year warranty and is dimmable in some fashion.
 

Patriots781

Active Member
Damn thats good idk what I'm doing wrong my light has the same footprint I'm in veg I got my light about 3.5 feet away how low do you dim during veg? Every time I try to push my plants in veg past 350 moles my plants get purple stems very dark green leaves and hate it and the plants come out the nodes stretch out and when I ran my 1000 watt hps the plants were much bigger and my node spacing was tighter, I I'm gonna try to do a cmh or hps for veg get that structure then use the enlite for flower I guess it's just taking forever to dial this light in.I would love to say I'm doing much better with the less but I'm just not getting the results
 
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SSHZ

Well-Known Member
I vary my led height between 36 and 42 inches..... purple stems are a plants reaction to the UV- it's perfectly natural. If your leaves are showing some crinkling too, than it's most likely a Mg issues but if the leaves are healthy and just purple stems, they are fine. You may want to check out "sshz gavita" on google and read the orange gasm thread as there's great details.
 
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