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ppfd for cannabis

Cannabis

Legal disclaimer – MechaTronix LED grow lights for cannabis production are only sold to geographical territories where the growth of cannabis is legalized by local laws.

With the global trend towards legalization of cannabis growth for medicinal use, a new era of deeper research and knowledge in use and effects of phytocannabinoids as Tetrahydrocannabinol (THC) and Cannabidiol (CBD) finds its strive.

Recommended light levels PPFD and spectra at various cannabis growth stages and principles

Cannabis Seed Sprouts or Root Clones

Cannabis seed sprouting or root cloning in general don’t need too high light levels as the absorption capacity of plants in this stage is rather limited.
The lower heat signature of LED grow lamps allow close positioning of the lamps to the canopy what makes vertical farming at this stage a space effective solution.
Similar to most crops at this initial stage blue 450nm and red 660nm wavelengths give the best results, with a good balance between the energy levels of the two wavelengths to create an equilibrium of elongation and biomass production. The yellow/green spectrum 500-600nm has some effect but isn’t a real need as the leaf volume is still limited and the addressing of chlorophyll a & b and limited Phytochrome Pr are the main photoreceptors in initial stage creating photosynthesis.

Lights levels PPFD of 120 to 150µmol/sm² are sufficient at this stage but you might want to raise to 250µmol/sm² when you get closer to the vegetative stage to avoid too much elongation.

Advised spectra for cannabis seedlings and clones.

CoolGrow® RRB

CoolGrow® 3RBEQW

Cannabis Vegetative Growth

Blue 450nm mainly promotes more compact plants and stomata opening – we also recommend the use of far red spectrum 730nm at this stage as this triggers the phytochrome Pfr receptors and will tell your plant after the vegetative stage to go immediately into flowering mode.

The CoolGrow® 3REQWFR will give you strong larger plants with long internodes so more spindly crops.

CoolGrow® 3RBEQWFR

CoolGrow® 3REQWFR

Cannabis Flowering

PPFD level advised for cannabis flowering start at 650µmol/sm² up to 900µmol/sm² towards the end stage.

Advised spectrum for cannabis flowering CoolGrow® 3R2EQW.

CoolGrow® 3R2EQW

Cannabis cultivation with Sea of Green (SoG) methodology

When growing cannabis according the Sea of Green principles, there are a few important lighting parameters to take into account in order to decide on the ideal LED grow luminaire.

Recommended LED Grow Lights for cannabis cultivation

We differentiate our recommendation in function of the growth environment in which growers cultivate.
In indoor environments, both the CoolFin® and CoolStack® LED grow lights give excellent results.
Both luminaires deliver a stunning PPF up to 1.950μmol/s out of a 600 Watt grow light, all passive cooled by our advanced heat pipe technology.

When you grow in a greenhouse environment, you absolutely want to reduce the shade impact of the grow lights on you crops.
In that case the CoolStack® gives a perfect fit to the needs.
With a shade impact coefficient of just 100mm² per μmol this LED top light offers the lowest overall shading in greenhouse cultivation.

With the optical lenses you can adapt the beam angle to your practical growth room and required PPFD.
When you let us know your dimensions of the growth room, we will provide you with the optical simulation to get your lights right.

For personalized advise on your projects we recommend you to get in contact us.
Our expertise of over 20 years in lighting brings major technology driven advantages to the world of professional growers.

Legal disclaimer – MechaTronix LED grow lights for cannabis production are only sold to geographical territories where the growth of cannabis is legalized by local laws. Whether you grow cannabis Indica or Sativa, start from seedlings or cloning for your propagation, look at the vegetative stage or the deeper insights of flowering, light and the right light always is a key indicator for success you will have to under

Max PPF/PPFD with and without Co2

Smoke-A-Cola
Well-Known Member

Just trying to make sure I am putting the right amount of light in my new grow space. It is my understanding that adding Co2 allows for increased light levels.

What is the max ppf/ppfd you should be running with and without Co2?

PPFD is the better figure to use right?

weed-whacker
Well-Known Member

1000ppfd without and 1500ppfd with

according to. um let me find it

sorry can’t find it but its from a study paper done within the last decade

PhotonFUD
Well-Known Member

600 umoles. Plants can handle more, they just won’t use it.

If you want them to handle more, you can add in more CO2 above the 400ppm level but you need to keep the temperatures down under 30 celcius. >1000ppfd + >30 celcius has been shown to decrease the rate of photosynthesis.

You will have variances in strains and, of course, from your specific environment but those are safe starting points. Two things to keep in mind:

600 for the entire plant, not just the top with only

50 umoles hitting plant material below. High amounts of PPFD are great for the whole plant but you only get that with the Sun.
2. Consider increasing air circulation before adding in CO2. More air circulation will help increase CO2 to the plant and reduce temps.

Well-Known Member

600 umoles. Plants can handle more, they just won’t use it.

Icemud420
Well-Known Member

PPFD requirements vary by the length of the daylight. a plant in 18/6 will have different PPFD requirements than a plant in 12/12.

Search DLI or Daily Light Integral.

Icemud420
Well-Known Member

Here is the only study I have come across mentioning cannabis and PPFD.

PhotonFUD
Well-Known Member

PPFD requirements vary by the length of the daylight. a plant in 18/6 will have different PPFD requirements than a plant in 12/12.

Search DLI or Daily Light Integral.

loftygoals
Well-Known Member

This paper shows that with any canopy temp (20-40C) net photosynthesis increases upto a ppfd of 1500 umol/m2/s. That is without CO2.

Overall highest net photosynthesis occurs at 30C and 1500 umol/m2/s ppfd.

Attachments
Icemud420
Well-Known Member

I’ve seen mention of up to 65 mol/d and according to purdue university studies on different plant species, most other light loving plants like sunflowers and tomatoes are recommended for a DLI between 22 and 30mol/day.

So for cannabis, bottom threshold for optimal growth and photosynthesis is a DLI of DLI of 22 would be:
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

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: 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 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.

Smoke-A-Cola
Well-Known Member

That’s exactly what I was looking for, and then some!

CobKits
Well-Known Member

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

Icemud420
Well-Known Member

Great question, but I don’t know to be honest.. I mean based of DLI of 65, then yes, according to the math at 14 hours, would be a MAX PPFD of 1152.48 umol/m2/s-1.

If you go for the bare minimum accepted DLI of other sun loving plants at 22 mol/d, then the MAX (min) PPFD would be 390.07 umol/m2/s-1 at a 14 hour day.

So based on those 2 numbers its quite a range.

Using the forumula: DLI = PPFD x hours of daylight x 0.0036

Icemud420
Well-Known Member
MeGaKiLlErMaN
Well-Known Member

Easy answer, It will always help. but its not really needed till youre pushing way more light than we currently do. The drop off on this chart is where you need CO2. Supplementation will never hurt. but its not always as cost effective as people think. Even shorter answer. after 1500PPFD at 86F. good luck hitting that lol

MeGaKiLlErMaN
Well-Known Member

I’ve seen mention of up to 65 mol/d and according to purdue university studies on different plant species, most other light loving plants like sunflowers and tomatoes are recommended for a DLI between 22 and 30mol/day.

So for cannabis, bottom threshold for optimal growth and photosynthesis is a DLI of DLI of 22 would be:
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

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: 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 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.

Just trying to make sure I am putting the right amount of light in my new grow space. It is my understanding that adding Co2 allows for increased light…