THCFarmer.com
121,112 Members Log In Register
Log In Register

CAN SOME ONE DO A LIGHT METER READING ON LED'S PLEASE?

  • Thread starter Thread starter johnsmith_559
  • Start date Start date
  • Tagged users Tagged users None

CAN SOME ONE DO A LIGHT METER READING ON LED'S PLEASE?

johnsmith_559 82 Replies 12,125 Views
Page 3 of 5 · Replies 41–60 of 83
Status
Not open for further replies.
#41
Aqua Man said:
I just use the free app... better than a lot of those cheap ones and like I say I use it to ballpark.
Click to expand...
my phone maxed out at 17k so I bought an epsilon. Tried to use it to dial in the new led. I'm good now. Just bought another 100w hlg 4k to go with the 3k. Good mix.
 
#42
johnsmith_559 said:
the thing is once minimum spectral requirements it's all about the intensity . sort of like vitamins . you dont get bigger on proportion to the more you take. they meet the minimum requirements and then the rest are expelled. 2 lights the same out out both with different spectrums as long as they each have the minimum amount thr rest is about volume. doubling the par rating will do very little more . it is the same with the sun . it has a particular spectrum in the spring and summer but growth is similar. even the footcandles . there is 15000 + or 150000 lux on a bright day but we don't have plants significantly bigger than normal. size is also extremely relevant.things just dont double. they move in percentages relating to plant size . +/- 1 or 2% at a time . those crazy adds that say DOUBLE your harvest or EXPLOSIVE growth rate all fake terms that are meant to appeal to inexperienced customers. if a product adds more than 5% to your yield it means your were not doing some thing else in the first place
Click to expand...
Not true... not even close.

You cant use vitamins we are talking about spectrum... and yes more of any has thier effects... to match your analysis the more steriods the bigger the gains... see analogies are used support to an argument thats not able to be made.

Proven facts UV increase cannabinoid concentration and may other implications. The info you are using has been far disproven now and is outdated.
 
Last edited:
#43
In just going to link this.... again. There are plenty of links and references to actual scientific studies. Much like we know plants use photons outside of PAR. Green light is used in photosynthesis etc. All these claims are debunked and old.

www.frontiersin.org

Frontiers | An Update on Plant Photobiology and Implications for Cannabis Production

This review presents recent developments in plant photobiology and lighting systems for horticultural crops, as well as potential applications for cannabis (...
www.frontiersin.org www.frontiersin.org
 
#44
Aqua Man said:
Not true... not even close.

You cant use vitamins we are talking about spectrum... and yes more of any has thier effects... to match your analysis the more steriods the bigger the gains... see analogies are used support to an argument thats not able to be made.

Proven facts UV increase cannabinoid concentration and may other implications. The info you are using has been far disproven now and is outdated.
Click to expand...
post it
 
#45
here is one quote on par on wiki .
However, photosynthesis is a quantum process and the chemical reactions of photosynthesis are more dependent on the number of photons than the energy contained in the photons. Therefore, plant biologists often quantify PAR using the number of photons in the 400-700 nm range received by a surface for a specified amount of time, or the Photosynthetic Photon Flux Density (PPFD).[4] Values of PPFD are normally expressed using units of mol m−2 s−1. In relation to plant growth and morphology, it is better to characterise the light availability for plants by means of the Daily Light Integral (DLI), which is the daily flux of photons per ground area, and includes both diurnal variation as well as variation in day length.[5]
 
#46
now here is another very specific
It has been noted that there is considerable misunderstanding over the effect of light quality on plant growth. Many manufacturers claim significantly increased plant growth due to light quality (high YPF). The YPF curve indicates that orange and red photons between 600 and 630 nm can result in 20 to 30% more photosynthesis than blue or cyan photons between 400 and 540 nm. [8][9] But the YPF curve was developed from short-term measurements made on single leaves in low light. More recent longer-term studies with whole plants in higher light indicate that light quality may have a smaller effect on plant growth rate than light quantity. Blue light, while not delivering as many photons per joule, encourages leaf growth and affects other outcomes.[8][10]
 
#49
johnsmith_559 said:
now here is another very specific
It has been noted that there is considerable misunderstanding over the effect of light quality on plant growth. Many manufacturers claim significantly increased plant growth due to light quality (high YPF). The YPF curve indicates that orange and red photons between 600 and 630 nm can result in 20 to 30% more photosynthesis than blue or cyan photons between 400 and 540 nm. [8][9] But the YPF curve was developed from short-term measurements made on single leaves in low light. More recent longer-term studies with whole plants in higher light indicate that light quality may have a smaller effect on plant growth rate than light quantity. Blue light, while not delivering as many photons per joule, encourages leaf growth and affects other outcomes.[8][10]
Click to expand...
Nothing i don't already know... old and outdated info
 
#51
the point is that better light spectrum does not mean better growth .
we should be able to put 2 lights equal in wattage and if one is significantly better in PAR it should show that in growth but that is not what I see .
i see LED that may or may not have better spectrum performing at very close to hps and any difference can be explained by a higher light efficiency.
led puts out about 20% more light than hps and that is reflected in growth.
the 300 watt LED puts out the same FOOTCANDLE as a 400hps
the growth in the same space is about the same,
because the light simply puts out more light
 
#52
johnsmith_559 said:
now here is another very specific
It has been noted that there is considerable misunderstanding over the effect of light quality on plant growth. Many manufacturers claim significantly increased plant growth due to light quality (high YPF). The YPF curve indicates that orange and red photons between 600 and 630 nm can result in 20 to 30% more photosynthesis than blue or cyan photons between 400 and 540 nm. [8][9] But the YPF curve was developed from short-term measurements made on single leaves in low light. More recent longer-term studies with whole plants in higher light indicate that light quality may have a smaller effect on plant growth rate than light quantity. Blue light, while not delivering as many photons per joule, encourages leaf growth and affects other outcomes.[8][10]
Click to expand...
This sounds like the same shit they were talking about in 1970's. Grow lux vs HID.
 
#53
Aqua Man said:
In just going to link this.... again. There are plenty of links and references to actual scientific studies. Much like we know plants use photons outside of PAR. Green light is used in photosynthesis etc. All these claims are debunked and old.

www.frontiersin.org

Frontiers | An Update on Plant Photobiology and Implications for Cannabis Production

This review presents recent developments in plant photobiology and lighting systems for horticultural crops, as well as potential applications for cannabis (...
www.frontiersin.org www.frontiersin.org
Click to expand...
and after reading 4he article it says just that ...IT MAY have an increase but that has not be shown conclusively and not by a great amount .
 
#55
UH OH THE ENTIRE BUSINESS OF MARIJUANNA has just proved to be fake !
( because it's on wiki which is not allowed in school .I meant real science)
en.wikipedia.org

Cannabis (drug) - Wikipedia

en.wikipedia.org en.wikipedia.org
 
#58
Did you know Wikipedia is banned from use in schools? Im not saying everything is false but I am saying its not a reliable source of info.

Idk I'm just gonna drop it and agree to disagree. Read the studies in the links search out more... I have and there are plenty out there.

Try to give a minimum of each then blast them with green photons and let me know how that works. Plants do not absorb each spectrum equally not even close and each will have a saturation point so spectrum is absolutely relevant and important all use different receptors.

It's a pointless conversation as your here to prove something instead of debate. Been through this discussion to many times to bother again. The info is out there if you actually want it.
 
#59
i would imagine both articles about weed and light are fairly factual . there is discrepancy in a lot of article but I think the factual rating of the cannabis article is probably as factual as the light article.
I also don't see anything seriously wrong with the article you posted but it states in the preface it is only a working theory but like anything that is overly and precisely explained it may be taken far more intently than it was meant to be .every process in life can be over explained, such as 4he vitamins industry or weed industry and I find them both about as credible as each other lol
 
#60
mercury vapour is significantly less efficient in lumens per watt .that is the difference. put the same FOOTCANDLE reading on a plant as a LED and you will get similar growth. the difference will be the wattage taken to supply the FC light intensity required.
 
Status
Not open for further replies.
Page 3 of 5 · Replies 41–60 of 83
Back
Top Bottom