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Off the shelf retail store screw-in LED and CFL bulb comparisons
- Thread starter blynx
- Start date
PAR for plants, lumens are for people.
Soylent Green is people.
Soylent Green would be an excellent name for a strain,
if it isn't already.
Does Sylvania, or any brand for that matter, post information of PAR
Soylent Green is people.
Soylent Green would be an excellent name for a strain,
if it isn't already.
Does Sylvania, or any brand for that matter, post information of PAR
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i mean i'm not discounting your millions of dollars in research from people trying to sell shit to you...
but like i said people have done this lots of times. different spectrums and UVB will affect terpenes and shit like that. but the plant will not magically grow faster/slower better under one light or the other.
for instance strains flowered under more blue light tend to less stretchier, little leafier and slightly less weight than under red light. but it might be more frostier than under redder lights and tighter nugs. whereas under red light it will be stretchier, slightly more fluffier and not quite as caked up, but the yield is like 10% more.
but i've seen nothing saying plants will grow significantly faster under this light vs that light. there's different amounts of each color per bulb...but in the end it all evens out as far as bulbs are concerned since they still arent the sun which has all the colors and even more in a wider array and in higher concentrations.
if you really want the best. mix both types and lean slightly towards your favorite color in the amount of bulbs you use.
i rather liked the results i got from using an mH and an HPS together.
prolly doesn't look like much from this terribly lit terribly focused picture, but this thing is covered.
but like i said people have done this lots of times. different spectrums and UVB will affect terpenes and shit like that. but the plant will not magically grow faster/slower better under one light or the other.
for instance strains flowered under more blue light tend to less stretchier, little leafier and slightly less weight than under red light. but it might be more frostier than under redder lights and tighter nugs. whereas under red light it will be stretchier, slightly more fluffier and not quite as caked up, but the yield is like 10% more.
but i've seen nothing saying plants will grow significantly faster under this light vs that light. there's different amounts of each color per bulb...but in the end it all evens out as far as bulbs are concerned since they still arent the sun which has all the colors and even more in a wider array and in higher concentrations.
if you really want the best. mix both types and lean slightly towards your favorite color in the amount of bulbs you use.
i rather liked the results i got from using an mH and an HPS together.
prolly doesn't look like much from this terribly lit terribly focused picture, but this thing is covered.
Do you know what PAR is? I will give you a hint, it's not a unit of measure.
Lumens fall within the PAR spectrum.
Cree and Vero publish their Relative Spectral Power Distribution curves in their LED data sheets, I presume Sylvania would.
You wouldn't think, but 5000k bulbs and higher have more green and the plants barely absorb it, but once it's in there since the color of the plant is green, that green light present in higher temperature rated LED offers benefits such as the light beaming around once it's in there. It's similar to shining a red light in your finger to get oxygen saturation of blood. You can see the red light glows and shines light throughout the finger. This green light present in higher temperature kelvin bulb does that with the buds and leaves and it shines deeper inside the bud.
And yes, the visible electromagnetic spectrum is basically seen by the human eye in varying brightness, red being most bright, green being most dim (lumens) and most of it is photosynthetically active radiation (PAR) for the plant's chlorophyll. The human eye and PAR line up perfectly and overlap. There are several different light absorbing pigments. Purple or anthocyanin, I assume is a plant's way of trying to heat up with light, due to the coldness. Peaks absorption spectra are blue and red in chlorophyll a and b. Blue being the the weird one, favoring leaf growth, while red is using for flowering.
And yes, the visible electromagnetic spectrum is basically seen by the human eye in varying brightness, red being most bright, green being most dim (lumens) and most of it is photosynthetically active radiation (PAR) for the plant's chlorophyll. The human eye and PAR line up perfectly and overlap. There are several different light absorbing pigments. Purple or anthocyanin, I assume is a plant's way of trying to heat up with light, due to the coldness. Peaks absorption spectra are blue and red in chlorophyll a and b. Blue being the the weird one, favoring leaf growth, while red is using for flowering.
chronosync
Well-known member
OK interesting, but how does green light beaming around a box benefit a plant if they barely absorb it?
HuffnPufferfish
Member
who cares, we're stuck what we can buy anyway
if you knew 100% what par you required, then what?
if you knew 100% what par you required, then what?
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I heard a lotta buzzy language and some jazz about green light which we ALL know from 5th grade science plants cannot absorb which is why plant life looks green to our eyes. Your eyes only see reflected light. So yeah anyway you were trying to sell us bulbs? Cob cree leds?
HuffnPufferfish
Member
yeh but they DO absorb it, it just that there A LOT of it in the air around them so its not a 'priority' but people who think they dont need it, are simply wrong
It's a stoner myth, plants absorb green very well as proven by Kieth Mcree in 1972 http://www.inda-gro.com/IG/sites/default/files/pdf/ACTION-SPECTRUM-KJMCCREE.pdf
"Absorptance of green light (550 nm) is only
15% less than the average absorptance across the PAR region. The relative action of green light (550 nm) is only 9% less than the average relative action across the PAR region".
yea. sell you bulbs. No, unfortunately I don't have any to sell.
I am just saying that green added is beneficial. I guess I could have said it in one sentence like that at first to make it easier for you.
The term spectral power distribution refers to the concentration,
as a function of wavelength, the Rayleigh scattering effect is a
good example of this.
The amount of photons emanating from the sun is unchanged,
it’s an optical phenomenon that produces a concentration of
shorter wavelengths.
It's photons we're after, not wavelengths, however pretty the blue sky is.
Reputable horticultural lamp manufacturers do specify the
output of their lamps in PAR photons per second.
Lumens, which are measured according to what the
eye is sensitive to, is therefore not an accurate
representation of the grow light properties of a lamp.
If you count all the photons that a lamp emits in the PAR spectrum
per second you get the Photosynthetic Photon Flux.
That information will allow you to compare apples to apples.
Use your Ulbricht Sphere, or failing that, just look at your lamp
and blink really really fast to count the photons, lol
Its the amount of photons that is important, not the
brightness or wavelength, as others have suggested.
PAR for plants, lumens for people.
Good thread
HuffnPufferfish
Member
TheScrogFrog
Active member
A few girls under 6 x 8.5w Philips LED's.
Day 7 12/12
Just curious to see if I can pull 2oz from 51w of LEDs. So far looking pretty decent.
Other tent is running 8 x 14.5w(only draw 13.5w max each) too but I can't find my camera charger. The struggle.
Day 7 12/12
Just curious to see if I can pull 2oz from 51w of LEDs. So far looking pretty decent.
Other tent is running 8 x 14.5w(only draw 13.5w max each) too but I can't find my camera charger. The struggle.
I don't think there are any "reputable horticultural lamps" mentioned in this thread which is supposed to be about comparing retail store screw in bulbs. Perhaps you are in the wrong thread?
There are lux to PPF conversion tables for many popular LEDs on other forums.
You didn't answer my question do you know what PAR is?
If you do, then why do you end your posts with "PAR for plants, lumens for people."? It's like saying "VHF is for radios, electron volts are for people"
The first one in each case (PAR or VHF) is the shorthand for a range of wavelengths, the second (lumems or electron volts) are units related to energy, they are not directly comparable, hence the statement "PAR for plants, lumens for people" is nonsense.
chronosync
Well-known member
Mind. Blown. Or is that just for fuses?
Yea, we had some stoner scientists explain that all you need is blue and red to grow pot, all else was waste. Well, yes you can grow fine pot with just blue and red but the rest plays a role too.
The sun will never be equaled and intense sun being best. That said, my Philips 14 watt 5000 K LED lights are great for growing pot. Cut off the bulb and let em rip. I can place them within 1 inch of the plants.
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R
ratsidecar
Its just gone 4 weeks of 12/12. The hempy plants are getting very frosty, I tried to take good photos of it but it doesnt show up as well as it really looks.
The soil scrog plant is a bit behind the hempy ones but is still developing nicely. I can see that next time round it would benefit from another topping and putting the plant in the middle of the screen initially instead of at one corner so it can be trained out to fill it better.
The soil scrog plant is a bit behind the hempy ones but is still developing nicely. I can see that next time round it would benefit from another topping and putting the plant in the middle of the screen initially instead of at one corner so it can be trained out to fill it better.
R
ratsidecar
