Ppfd :-)

Moflow

Well-Known Member
I did a thread a while back and the calculations for ppfd from lumens/lux but just found it not quite so accurate.

Id love a meter - could post data on ppfd for plant stage, dont see or here much talk there even though ppfd is big with led and such

I hope the link works.
On Page 12 of pdf there's a chart.
It's on PAR with what I'd use for veg and flower.
I use 300- 400 for veg 24/0 and 700 - 1000 umols for flowering 12/12
It works great for me.

Another fella, dirtyninja says....
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.
 

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Kingrow1

Well-Known Member
Is that why you make HPS posts weekly still then troll?
Yes since new growers should know they have three choices and not just the singular one you shove down their throat.... Tis why i have to post on a few subjects but as soon as you start giving the full picture and not just your toxic singular one i wont be needed and can go back to making wise cracks and jokes on unrelated threads :-)
 

Kingrow1

Well-Known Member
On paper led rocks but in reality it cant match its paper data - is that a spectrum problem? Historically thats always been a stumbling block.

Im all for leds becomoling the best light but i just cant see it yet.

Personally its a non issue, i just hated how led posters hated on everyone else and thought there was a better way to co-exist.

Id also.like to see an even ppfd over the whole tent from leds, different voltages to each diode maybe idk but theres more they could push than just the basic models :-)
 

bk78

Well-Known Member
On paper led rocks but in reality it cant match its paper data - is that a spectrum problem? Historically thats always been a stumbling block.

Im all for leds becomoling the best light but i just cant see it yet.

Personally its a non issue, i just hated how led posters hated on everyone else and thought there was a better way to co-exist.

Id also.like to see an even ppfd over the whole tent from leds, different voltages to each diode maybe idk but theres more they could push than just the basic models :-)

Dude you grow in a 2x2 tent and grow autos to boot. Fuck outta here.
 

Kingrow1

Well-Known Member
HPS light sucks! Led can actually be spread even. Hps can't. Plus hps light is really bad for your eyes.
It dosent matter since cmh came alone - led never had the spectrum of hps or integrity over distance from low wattage multipoint light sources that hps has and the wider cmh spectrum didnt increase much over hps.

In the end all i saw were three different lights that in the right hands were all awesome and similar.

Some have noted some of the best spectrums come from the exspensive fish hobby t5's - closest of all to daylight.

An exspansive subject but take all that away and we have ppfd per plant stage and lights set per distance per ppfd per stage - pretty cool for us growers right :-)
 

Kingrow1

Well-Known Member
Dude you grow in a 2x2 tent and grow autos to boot. Fuck outta here.
Ive grown lots of ways but good job at alienating every member here with a small tent and autos.

You should see my dick though - thats massive :-)
 

Kingrow1

Well-Known Member
EyeHorti MH Blue Daylight. Used by most research centers and universities.
An awesome daylight light - do the tri coatings of exspensive phosphours still not exceed it? I know flouros are crap for deep blues and uvs why those tubes sell in the fishtank industry seperately and you can mix tubes to even greater effect.

Jurys out for me there :-)
 

rkymtnman

Well-Known Member
An awesome daylight light - do the tri coatings of exspensive phosphours still not exceed it? I know flouros are crap for deep blues and uvs why those tubes sell in the fishtank industry seperately and you can mix tubes to even greater effect.

Jurys out for me there :-)
I used one for a bit. Really needed 2 to cover my area properly but the plants did love it. Threw off a crapload of heat though. Like any MH.
 

rkymtnman

Well-Known Member
only 2 lights i haven't tried: plasma and induction. both seemed overpriced only good for veg lights.
 

Kingrow1

Well-Known Member
why is this so?
Laws of physics and many years of spectrum compensation - its not very full compared to other light types.

I.mean i dont want to really debate it futher, leds have backed of a lot and we all happily get along, cmh was a wide full spectrum but still not much gains and it complicated the led hype.

Everyone can say one is superior but in reality if anything was that superior we would all run it and the others would die overnight by logic :-)
 
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