# Lumens Vs Spectrum



## RickWhite (Jan 30, 2010)

Is there and reliable data on what is more beneficial to a plant?

It seems that my 250W Hortilux Blue MH with a 6500K temp is outperforming my 600W Hortilux HPS for vegitative growth.

It's hard to tell but I'm wondering if going with the 1000W 6500K MH for the entire grow isn't the way to go. Or maybe, the new ceramic MH bulbs.


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## FuZZyBUDz (Jan 30, 2010)

well a 1000 watt HPS kiks out like 140000 lummens but a a MH kiks out 100000, but with the HPS u will deffinately have sum dence buds, MH have a risk of a more airy buds with the less lummens, but u really got more potency out of the MH compared to the HPS.


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## satica (Jan 30, 2010)

I begin with metal halide 600 watt for veg that keep the plants shorter and thicker.when Flowering comes I just switch to one day metal halide and one day 1000 watt HPS .

overally, IMO it is the best way to use good thoings of MH and HPS. I think MH has been under rated .Its a good source of light especially for veg.

In your case if it is outperforming your 600 watt hps then maybe something is wrong with your hps ballast or bulb since the difference is not that much .

peace


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## T.H.Cammo (Jan 30, 2010)

*Lumens Vs Spectrum* 



RickWhite said:


> Is there and reliable data on what is more beneficial to a plant?
> 
> It seems that my 250W Hortilux Blue MH with a 6500K temp is outperforming my 600W Hortilux HPS for vegitative growth.
> 
> It's hard to tell but I'm wondering if going with the 1000W 6500K MH for the entire grow isn't the way to go. Or maybe, the new ceramic MH bulbs.


I'm not sure, exactly, what you're asking! But how's this?

A whole bunch of lumens won't do a damn bit of good, if they're the wrong spectrum. But even a single, little 25 watt, "Daylight" CFL will Veg something - impressively well!

"Spectrum" is of paramount importance, "lumens" is a slippery slope!


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## RickWhite (Jan 31, 2010)

I have used the enhanced blue HPS bulbs for some time and have hed decent results. But, other than conventional wisdom, I have yet to see anything concrete that demonstrates any benefit from a HPS vs a MH. In fact, I am beginning to wonder if running exclusivly MH isn't the better way to go. After all, people get great results from MH as well.


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## plaguedog (Jan 31, 2010)

Does anyone have any experience with the Ceramic Metal Halide bulbs? They put out less lumen per watt but supposedly the spectrum has much more blue then the standard HPS and much more red then the standard MH. I think 250 watt and up they can only be used in a standard magnetic ballast, not digital. I'm really thinking about getting one for my small 250 hps grow.

here is another site with decent info on them: http://www.icmag.com/ic/showthread.php?t=72215


Here are some other newer technology lights also known as CDM from phillips. Supposedly the 210 watt light is comparable to a 400 watt MH with a fuller spectrum.
http://www.lighting.philips.com/us_en/applicationsolutions/retail/cdm_elite_medium/index.php?main=us_en&parent=0&id=us_en_application_solutions&lang=en


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## RickWhite (Jan 31, 2010)

plaguedog said:


> Does anyone have any experience with the Ceramic Metal Halide bulbs? They put out less lumen per watt but supposedly the spectrum has much more blue then the standard HPS and much more red then the standard MH. I think 250 watt and up they can only be used in a standard magnetic ballast, not digital. I'm really thinking about getting one for my small 250 hps grow.
> 
> here is another site with decent info on them: http://www.icmag.com/ic/showthread.php?t=72215
> 
> ...


I am also very interested in these bulbs. They come in up to 400W and use a standard HPS ballast. Not digital and not switchable.

But yes, they are an almost perfect spectrum. Hortilux however, makes a 1000W blue bulb with agreat spectrum though not as much reds as the CMH. But, from what I have been noticing, it looks like the plant uses the red spectrum to grow stem and the blue to grow foliage. I want foliage, not stem.


________________________________________________________________________________________________________________________


On another note, has anyone ever seen proof that higher reds promote better flowering? What I've heard is that some believe that the harvest sun includes more red light so it must stand to reason that more red promotes flowering. I'm not convinced this is true. If anyone has proof, I'd love to see it.


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## lmn8r (Feb 1, 2010)

Plants are designed to grow in the *SUN*... Any artificial light that comes closer to that will give better results.

High pressure sodium works because of it's raw power and efficiency. It concentrates nearly all it's energy as light into that ugly orange color peak around 589nm wavelength. Plants only absorb that type of light moderately, because it's not in the "butter zone" of photosynthesis. It is however, fairly close which is why it's used for flowering, and like I mentioned, it's raw power makes up it's lack of absorption.

CMH lamps such as the Philips MasterColor series give off a little bit more red then the Hortilux Blue. In my opinion, CMH bulbs have the highest percentage of light absorbed by the plants when compared to all other grow light technologies. They are less efficient then HPS, more of their light is useful light within the 400-450nm blue and 600-700nm red range.

It's mathematically calculable how much useful energy to a plant each type of lighting technology gives out. I did the calculations; 

I compared an EYE Hortilux Super HPS 400w bulb to a Philips MasterColor 400w CMH. The HPS bulb gives 55,000 initial lumens for 137 lumens/watt and the CMH bulb gives 34,800 initial lumens for 87 lumens/watt.


Assuming all the factory specs, and rounding lumens down, I calculated the relative energies at 10 nanometer wavelength intervals from 400nm-700nm within the visible light spectrum; A total of 31 different measurements. I then compared Clorophyll A and B photosynthesis at each wavelength interval, and ran the numbers.

In the end it turned out the HPS bulb had 12,318 lumens worth of useful photosynthetic penetration. This beat the CMH bulb with 9,903 lumens worth of useful photosynthetic penetration; The HPS beating the CMH bulb by roughly 124% overall. Predictably though, the CMH had a higher percentage of it's light used for photosynthesis, 28% of it's light used versus only 22% from the HPS.

Looking at a narrower scope, just veg/flower colors, the HPS is 141% better at flowering then the CMH, producing 4935 useful lumens within the 600-700nm "butter zone" compared to the CMH's 3478 lumens. The CMH had the HPS beat though for vegetative stage, 850% better at the 400-450 blue spectrum. The HPS only mustered 416 useful blue spectrum lumens, compared to the CMH 3514 lumens. Keep in mind though, this is a horticultural bulb with an enhanced spectrum, standard security light HPS would lose hands down to CMH.

The conclusion? It's still not clear. If you had to use a single bulb throughout the whole grow, the CMH may have the advantage because it handles the veg. stage so much better, while only trailing HPS during flowering. On the other hand, if you have the option of swapping out bulbs, you'll want to use the CMH for veg. and HPS for flowering. If your looking for the best possible light conditions, I would suggest one of each. What's interesting is the normal metal halides can easily push 110 lumens/watt. If they are to improve CMH technology in the future to make it more efficient while keeping the same spectrum, at that level it will beat out the HPS in all circumstances.

My personal opinion about CMH bulbs; I think they're the best artificial light source for growing yet, beating out HPS. The balanced spectrum plus UV light emitted from CMH bulbs has additional, unmeasured benefit for flowering cannabis. I'm convinced, but until someone compares the two in laboratory conditions a lot of people won't be. Your welcome to make your own conclusions.

If anyone wants to see my spreadsheet with all the numbers let me know i'll post it.


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## Uncle Ben (Feb 1, 2010)

RickWhite said:


> I have used the enhanced blue HPS bulbs for some time and have hed decent results. But, other than conventional wisdom, I have yet to see anything concrete that demonstrates any benefit from a HPS vs a MH.


There isn't, I've done the experiment using a regular HPS from start to finish. There was none of the favorite forum paradigms - excessive stretching, lack of potency, poor plant health, etc. Both lamps are full spectrum, it's just that when folks look at the spectral output graphs, they think the plant needs more of this and that. Spectral output is overdone, just like nutes, additives, and all the other stuff folks tend to throw at their plants.

Vendors are the ones that really play the spectrum thing up, as they should - they're in it for the money. Conversion lamps, hoods, enhanced this and that.....it's all about the money. Plant doesn't care, only its owner cares.


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## RickWhite (Feb 1, 2010)

lmn8r said:


> In the end it turned out the HPS bulb had 12,318 lumens worth of useful photosynthetic penetration. This beat the CMH bulb with 9,903 lumens worth of useful photosynthetic penetration; The HPS beating the CMH bulb by roughly 124% overall.
> 
> Do you mean 24%?
> 
> ...


I'd love to see it. In fact, can you upload the file? Also, I'd like to see the literature you are using to determine what wavelengths are the most effective for vedge and flower. Do you know anything about what wavelength produces stem elongation?


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## Uncle Ben (Feb 1, 2010)

lmn8r said:


> If anyone wants to see my spreadsheet with all the numbers let me know i'll post it.


Thanks. I too have graphs since I studied this stuff to death. Here's an example of one lamp plants.


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## RickWhite (Feb 1, 2010)

So UB, you are saying that sheer light output trumps color?

have you also tried an all MH grow?


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## RickWhite (Feb 1, 2010)

OK, I did some reading and it appears that the important wavelengths for plants are 425nm - 475nm & 650nm - 700nm.

The CMH bulb in a 4000K color produces around 15 times more relative energy in the blue range and 3-4 times as much relative energy in the reds than does a bulb such as the Sun Agro HPS. I forget what the overall difference in Lumens is but it is nowhere near these numbers.

Unless I am dramatically misunderstanding something, the CMH should be far more effective.


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## figtree (Feb 1, 2010)

Yeah rick, blue spectrum is better for veg, but if you can have both your even better. i actually use 6500 for veg and 2500 for bloom. i wish i could use both for both all the time. each spectrum will benefit in a different way, ie....blue is good for leaves and foliage, and red is good for roots and flowers.
This is a good question for the LED bunch, less lumens but right where you want with the spectrums.
fig.


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## jawbrodt (Feb 1, 2010)

I just wanted to add that the OP _could_ be mistaken about the 250 MH beating the 600 HPS. It's a common for new growers to mistake stretching for vigorous growth, as I've done this myself, in the very beginning.LOL


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## RickWhite (Feb 1, 2010)

jawbrodt said:


> I just wanted to add that the OP _could_ be mistaken about the 250 MH beating the 600 HPS. It's a common for new growers to mistake stretching for vigorous growth, as I've done this myself, in the very beginning.LOL


No, I'm no noobie. Forget the watts - the Lumens are the same the way I have them arranged.

The key is that the MH is a 6500K bulb. The difference seems fairly clear - way more bushy and the leaves really reach for the bulb where as with the HPS they just kind of hang there.

I might just bud one on it's own under the MH to see how it compares.


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## lmn8r (Feb 1, 2010)

http://spreadsheets.google.com/ccc?key=0AgP0HYMXyb5VdFZQUjI5bi1ROXlSVjN3RnB1S2FiZEE&hl=en


My apologies if I made any math mistakes, it was late and I had been programming all night. Your right about the percentages, I was thinking like a computer, where 100% == 0. The two main measurements are the relative energies and Chlorophyll absorption percentages, which are taken from another study probably unrelated to cannabis. Without knowing the nuances of the cannabis plant, all I can offer is each bulb's useful spectra for photosynthesis. 

One thing you should forget is the whole "6500k" kelvin color temperature system. This is a system that shows how _humans_ perceive light, not how plants do.


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## jawbrodt (Feb 2, 2010)

RickWhite said:


> No, I'm no noobie. Forget the watts - the Lumens are the same the way I have them arranged.
> 
> The key is that the MH is a 6500K bulb. The difference seems fairly clear - way more bushy and the leaves really reach for the bulb where as with the HPS they just kind of hang there.
> 
> I might just bud one on it's own under the MH to see how it compares.


 
Ahhh, okay. Sorry about that.


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## Mcgician (Feb 2, 2010)

I'm conducting a test trial right now, but it's between a standard EYE Hortilux Super HPS 1000W bulb vs one of the new Sun Pulse 1000W in the 3K spectrum. This is a halide bulb in case you weren't aware. In 4 weeks I should have some more definitive answers.


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## plaguedog (Feb 2, 2010)

Well one thing is the CMH bulbs are about the same price point or lower then the expensive hortilux bulbs I believe. And if you want to cut down on heat a little bit they run somewhat cooler. The CMH also has a more comparable output curve as an hps, it lasts longer then a standard MH. I don't have one but I think I will purchase one and just see for myself when my hps bulb takes a dump.


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## Uncle Ben (Feb 2, 2010)

RickWhite said:


> So UB, you are saying that sheer light output trumps color?
> 
> have you also tried an all MH grow?


I'm saying that both are full spectrum lamps. I have known people who swear by MH exclusively. IOW, it doesn't matter. Choose the most efficient hood you can and go with a 600W HPS for your best bang for the buck. You're buying light.

I have been in these age old discussions on light spectrums for years. It comes down to alot of theory and little real world application. You just have to do the experiments.

Attached is a spectral graph of an Osram Sylvania HPS.


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## lmn8r (Feb 2, 2010)

Sadly it will likely remain a discussion as long as cannabis remains illegal and socially taboo; as it's tough for universities and research institution to get grants to study it. Until a standardized measuring system for plant growth is created for light bulbs, or peer reviewed scientific analysis is done, it's all going to be he said she said. After all, I doubt there are many PhD's lurking in this forum.

@plaguedog

No one light runs much hotter then any other. It's easy to calculate how much energy as heat each light outputs. The maximum luminous efficacy is 683 lumens/watt; therefore say a 400 watt HPS outputting 50,000 lumens outputs 125 lumens/watt. That calculates to 18% light, 82% heat. 82% of 400 watts is 328 watts of heat.

A 400 watt Philips CMH bulb for instance outputs 34,800 lumens @ 87 lumens/watt. 12% of it's energy is light so 88% is waste heat, or 352 watts. 352 compared to 328 is negligable. A 24 watt difference = 82 BTU's/hour, or a difference of 1.6 degrees F for a 4x2x8 small closet or 4x4x6 grow tent.


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## RickWhite (Feb 2, 2010)

Glad to hear someone is doing a trial. I might also bud a plant under the 250W blue MH for comparison.

From the graphs it is clear that the CMH and the Hortilux Blue emit more light in the ranges used for photosynthesis. Does anyone know what the Y axis ("relative energy") actually means? Because looking at them it seems that the plant can not use most of what the HPS puts out.

If anyone can attach a spread sheet I would like to bump up the whole spectrum to see what it looks like.

UB, I hear what you are saying but it just doesn't jive with what I am looking at. I know people grow well with both but these newer bulbs merit some study I think.


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## RickWhite (Feb 2, 2010)

lmn8r said:


> Sadly it will likely remain a discussion as long as cannabis remains illegal and socially taboo; as it's tough for universities and research institution to get grants to study it. Until a standardized measuring system for plant growth is created for light bulbs, or peer reviewed scientific analysis is done, it's all going to be he said she said. After all, I doubt there are many PhD's lurking in this forum.
> 
> @plaguedog
> 
> ...


Can you attach your spread sheets?

Also, I'm wondering how you got the figures you did earlier because based on relative energy I found the CMH to put out something like 15 times as much light in the one useable peak and 3-4 times as much in the other over the HPS. The difference in overall light was only about 42% more for the HPS.

Your figures were far different - 'd like to see how you got there.


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## Mcgician (Feb 2, 2010)

RickWhite said:


> *Glad to hear someone is doing a trial. I might also bud a plant under the 250W blue MH for comparison*.


No problem. My analysis will be as impartial as I can be. I play no favorites here, although I'd like to think I spent my money wisely. We'll see I guess. The problem I have is that I'd like to narrow down the variables in the equation more than they are and make it a truly scientific analysis, but my grow room isn't quite a real laboratory. What would constitute "evidence" exactly in this case btw? Overall plant growth, including photosynthetic response, or just dried bud weight? I'm willing to guess most people only care about dried bud weight-I know that's what I'm focusing on. And Rick, time to step up to a larger light man. 250 watts is small time, lol. *stick-poke* J/K.


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## Uncle Ben (Feb 2, 2010)

RickWhite said:


> UB, I hear what you are saying but it just doesn't jive with what I am looking at. I know people grow well with both but these newer bulbs merit some study I think.


OK. People see what they want to see too.

Are you saying you're using a "newer" bulb and have empirical evidence that it is superior, or is this discussion just rhetoric based on theory or the latest forum chatter, or what we choose to believe, blind faith? Did the hydro man say it was so?


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## RickWhite (Feb 3, 2010)

Uncle Ben said:


> OK. People see what they want to see too.
> 
> Are you saying you're using a "newer" bulb and have empirical evidence that it is superior, or is this discussion just rhetoric based on theory or the latest forum chatter, or what we choose to believe, blind faith? Did the hydro man say it was so?


What I'm saying is that according to all the literature, photosynthesis is driven by light from two points in the color spectrum. 425nm-475nm and 650nm - 700nm. If one were to use a light that emitted only 500nm - 600nm, very little growth would occur.

According to the published graphs, which is the best I have right now, a CMH compared to an enhanced HPS, emits about 42% less overall light but 15 times more in the blue peak and 2-3 times as much in the red. Or vice versa - i forget.

Looking at the math:

The HPS:

Assume a value of 2 for the red and 142%. 2(1.42)= 2.84

Assume a corresponding value of 6 for the CMH at 100% 6(1)=6

6/2.84=2.11

So for the one peak which is where photosynthesis occurs, the CMH should put out more than twice as much usable light.

At the other peak you get 15(.79)=11.85 or almost 12 times as much usable light.

Of course I am only crunching numbers according to what I see on the graphs of relative energies. I do not know how the term relative energy is being used or exactly what the graphs represent. Nor do I have any actual data. If the graphs show how much blue is emitted in relation to how much yellow, my calculations could be erroneous because this shows only a relation and not actual output.

In other words, the graphs are shown in relation to a yellow spike. If all data points were squared, the spectrum's might look more similar with the HPS just showing one yellow spike off the chart. This yellow spike might be 1% of total output.

I'm not sure if the graphs show relation of color to output or color to other colors.


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## Uncle Ben (Feb 3, 2010)

RickWhite said:


> What I'm saying is that according to all the literature, photosynthesis is driven by light from two points in the color spectrum. . If one were to use a light that emitted only 500nm - 600nm, very little growth would occur.


That's true but like I said, MH and HPS are full spectrum lights. Maybe your argument is that you think that more output in the 425nm-475nm and 650nm - 700nm range would be beneficial? I finally broke down and went to a HPS enhanced lamp. Really didn't see any difference in plant response. Like I said, you'll just have to let loose of the theory and try it out for yourself.

good luck,
UB


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## lmn8r (Feb 3, 2010)

*http://spreadsheets.google.com/ccc?key=0AgP0HYMXyb5VdFZQUjI5bi1ROXlSVjN3RnB1S2FiZEE&hl=en*

You can find the spreadsheet there. ^^
You can find the spreadsheet there. ^^
You can find the spreadsheet there. ^^
You can find the spreadsheet there. ^^
You can find the spreadsheet there. ^^
You can find the spreadsheet there. ^^

Neither HPS or MH are "full spectrum" lights. Only black body radiators, such as tungsten incandescent, or.. the sun emit a full spectrum of EM radiation in the visible light wavelengths. Even lights with high CRI such as cermic metal halide, or short arc xenon bulbs have dips and peaks in their spectra, as well as D-line emissions from their root elements.

I think lighting with the most potential right now are LED lights, because they can be tuned perfectly to the right colors a plant needs. The only problem is they're woefully inefficient compared to sodium vapor light. They'll eventually come down in price but I don't see anything to suggest they'll be ever be able to beat 100 lumens/watt.


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## sizzilky (Feb 4, 2010)

<3 u uncle ben u da man


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## tea tree (Feb 4, 2010)

veg with t5 or metal halide. flower with hps.


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## Uncle Ben (Feb 4, 2010)

lmn8r said:


> Neither HPS or MH are "full spectrum" lights.


I'm sho glad mah plants can't read! Whew doggies.......


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## HomeGrownHairy (Feb 4, 2010)

RickWhite said:


> Is there and reliable data on what is more beneficial to a plant?
> 
> *It seems that my 250W Hortilux Blue MH with a 6500K temp is outperforming my 600W Hortilux HPS for vegitative growth.*
> 
> It's hard to tell but I'm wondering if going with the 1000W 6500K MH for the entire grow isn't the way to go. Or maybe, the new ceramic MH bulbs.


Data? Prolly, somewhere but, yes, and that's the way it should be. I use a 250 mh for veg and a 400hps for flowering. The higher spectrum K's are better for veg. Far as a 1000w mh, if I were going to use a single HD type bulb throughout the grow, I'd have to grow with an hps, not a mh.


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## RickWhite (Feb 4, 2010)

lmn8r said:


> *http://spreadsheets.google.com/ccc?key=0AgP0HYMXyb5VdFZQUjI5bi1ROXlSVjN3RnB1S2FiZEE&hl=en*
> 
> You can find the spreadsheet there. ^^
> You can find the spreadsheet there. ^^
> ...


Thanks, but would you tell me what the headings mean? Where did you get these figures?


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## RickWhite (Feb 4, 2010)

Uncle Ben said:


> Maybe your argument is that you think that more output in the 425nm-475nm and 650nm - 700nm range would be beneficial?
> UB


Well, since these are the ranges in which photosynthesis occurs it makes sense that a lamp that emits more of this light would be more effective than one that emits only a small percentage of its total output in this range. Anything outside these areas is waste.


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## sagensour (Feb 4, 2010)

Ive got a 6x7 room vegging out right now(2 week old babies). Im useing 2-1000watt switchables. Running 1-CMH and 1-HPS (eye hortilux) right now(20-4) and will veg for a couple more days till the babies are 11 inches tall. Im building a Scrog screen and installing tonight or tomorrow. I will start a journal with HPS vs CMH tonight. We can compare results. Thanks


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## lmn8r (Feb 4, 2010)

CMH only comes in sizes up to 400w. Technically, the Hortilux blue/EYE Quartz Arc HCR bulbs are not classified as CMH, even though they emit a comparable spectrum.

I assume the two grow areas are separate light-wise? Make sure the gals are of similar size and weight, give them equal watering, equal temps, equal nutes.


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## Uncle Ben (Feb 5, 2010)

RickWhite said:


> Well, since these are the ranges in which photosynthesis occurs it makes sense that a lamp that emits more of this light would be more effective than one that emits only a small percentage of its total output in this range. Anything outside these areas is waste.


You're referrring to PAR. 

I understand, you would think that. Doesn't hold true in the real world though, it's like the plant doesn't care as long as both red and blue spectrums are there. I too researched for hundreds of hours for the "perfect lamp" regarding PAR and gave it up when I tried an experiment, which showed me the spectrum this and that is all hooey. Had a acquaintance many years ago who said the same thing. He and his kids tried an experiment using different colored lights on beans and found no difference. 

UB


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## figtree (Feb 5, 2010)

RickWhite said:


> Well, since these are the ranges in which photosynthesis occurs it makes sense that a lamp that emits more of this light would be more effective than one that emits only a small percentage of its total output in this range. Anything outside these areas is waste.


Rick, I agree.

I have both spectrums going 2700 and 6500 kelvin and what i notice from my observations is the the plants tend to lean and grow towards the bluer of the light 6500 kelvin. I'm not really up to speed with the exact spectrums that plants use, but the little research ive done gives me the incling to think if your in the exact spectrum the plants need, it would be nothing but beneficial. and if you can get a bulb that only produces those spectrums with enough photons...... it would be explosive growth. I have been watching the led industry (not real close) in hopes i can switch when the prices come down and the technology gets up to speed.

Now from what i understand, plants are using spectrums that humans dont generally see, or seem very dim to our eyes, just cuz we dont see it doesnt mean its not getting massive photons. ie.... led lighting. gives off less visible light to us but the photons its dumping onto the plant are really what the plants are using.

Great conversation guys!
Fig


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## majikmerlin (Feb 5, 2010)

Amazing read! Thanks all!


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## Uncle Ben (Feb 6, 2010)

figtree said:


> Rick, I agree.
> 
> I have both spectrums going 2700 and 6500 kelvin and what i notice from my observations is the the plants tend to lean and grow towards the bluer of the light 6500 kelvin.


I think you're referring to a hormonal response called phototropism, has nothing to do with the spectrum, unless a certain spectrum influences the auxins found in the stem/petiole tissue, which I don't believe it does.


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## RickWhite (Feb 6, 2010)

Uncle Ben said:


> You're referrring to PAR.
> 
> I understand, you would think that. Doesn't hold true in the real world though, it's like the plant doesn't care as long as both red and blue spectrums are there. I too researched for hundreds of hours for the "perfect lamp" regarding PAR and gave it up when I tried an experiment, which showed me the spectrum this and that is all hooey. Had a acquaintance many years ago who said the same thing. He and his kids tried an experiment using different colored lights on beans and found no difference.
> 
> UB


Yes PAR watts. And from what I am finding most of the HPS bulbs do emit the highest PAR watts even though their graphs suggest otherwise. I don't think the theories are wrong, just that they are not well represented by those color spectrum graphs. I have experience producing graphs of this type so I know how missleading they can be.

See, because a HPS makes a huge yellow spike, the whole graph is pushed way down. That is why I would like access to such a graph. I would omit the yellow spike which would bring the rest of the graph up so we could see the rest of the spectrum.

From my Googling, it appears this might be the best HPS on the market. And it is made by an impressive company.

http://www.ushio.com/files/specs/hiluxgro.pdf

The Hotilux, Sunmaster and Sylvania also claim high PAR wattages. I ran across a list somewhere but can't find it now.


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## GrowingfortheGold (Feb 6, 2010)

Uncle Ben said:


> I think you're referring to a hormonal response called phototropism, has nothing to do with the spectrum, unless a certain spectrum influences the auxins found in the stem/petiole tissue, which I don't believe it does.


Most people think that you have phytocromes and cryptochromes. The first respond to red light and the latter responds blue light.

It isn't as simple as that. Phytocrome-B also responds to Blue light.

I guess what I'm trying to say is that plants are very vry complex entities...much like anything else that is living. It is more of a sum of parts that affects plant growth than say one variable (spectrum). Nonetheless, I will continue to use super blue for my veg. Although it is worthy to note that many super blue bulbs emit a lot of UV light. This UV light can easily bleach a young plant. Simple fix is to get an air cooled hood as the glass pane will absorb and lower total UV output.

Study on auxins and light spectrum in moss. Light spectrum does effect auxin development, however the overall extent is debatable. Cryptochromes do not solely regulate auxin development so like I said sum of the parts...

Summary
http://www.plantcell.org/cgi/content/abstract/14/2/373

The actual study
www.plantcell.org/cgi/reprint/14/2/373.pdf

-GFTG


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## Uncle Ben (Feb 7, 2010)

RickWhite said:


> Yes PAR watts. And from what I am finding most of the HPS bulbs do emit the highest PAR watts even though their graphs suggest otherwise. I don't think the theories are wrong, just that they are not well represented by those color spectrum graphs. I have experience producing graphs of this type so I know how missleading they can be.
> 
> See, because a HPS makes a huge yellow spike, the whole graph is pushed way down. That is why I would like access to such a graph. I would omit the yellow spike which would bring the rest of the graph up so we could see the rest of the spectrum.
> 
> ...


Those lamps look good. When my old HPS went down, this is what I bought. http://www.wholesale-garden.com/article_bss228131.asp


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## RickWhite (Feb 7, 2010)

UB, that is supposed to be one of the best bulbs from what I can find.

It is too bad more manufacturers don't advertise PAR wattage or publish more concrete data on their lamps. Sunmaster does publish PAR wattage. And the Growlux you linked to claims to have the highest PAR of any US made bulb. I think the Hortilux is somewhere around 211.

Anyway, so far the only thing known for sure is that LEDs emit far better PAR on a watt per watt basis but they are just too expensive to be in the running. It would be nice if the price of these comes down.


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## Uncle Ben (Feb 7, 2010)

RickWhite said:


> UB, that is supposed to be one of the best bulbs from what I can find.
> 
> It is too bad more manufacturers don't advertise PAR wattage or publish more concrete data on their lamps. Sunmaster does publish PAR wattage. And the Growlux you linked to claims to have the highest PAR of any US made bulb. I think the Hortilux is somewhere around 211.
> 
> Anyway, so far the only thing known for sure is that LEDs emit far better PAR on a watt per watt basis but they are just too expensive to be in the running. It would be nice if the price of these comes down.


LED lighting will replace most lighting, I think. Prices will surely come down but for now HID is the best bang for the buck.


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## FuZZyBUDz (Feb 7, 2010)

Uncle Ben said:


> LED lighting will replace most lighting, I think. Prices will surely come down but for now HID is the best bang for the buck.



i wouldnt mind using LED, mayb along the sides or the bottom of my grow room, but i really couldnt afford it.


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## madcatter (Feb 8, 2010)

I vegged a crop under LED's and they grew very well.... but when it comes to flower time, there is not near enough lumens and intensity.... so HID for the flowering stage for me for sure...


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## figtree (Feb 8, 2010)

Uncle Ben said:


> I think you're referring to a hormonal response called phototropism, has nothing to do with the spectrum, unless a certain spectrum influences the auxins found in the stem/petiole tissue, which I don't believe it does.


Yes phototropism, if its not the spectrum the plants liking then what is it that makes it "PHOTOTROP"? same types of bulbs, same strain, same watttage, same lumens, same distance from the canopy, only difference is the spectrum, yet per my observations the 6500kelvin generates more growth, faster growth, and stretching towards that specific spectrum. What other factors would be in play in this situation that would make it stretch towards a certain spectrum?


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## Uncle Ben (Feb 8, 2010)

figtree said:


> Yes phototropism, if its not the spectrum the plants liking then what is it that makes it "PHOTOTROP"? same types of bulbs, same strain, same watttage, same lumens, same distance from the canopy, only difference is the spectrum, yet per my observations the 6500kelvin generates more growth, faster growth, and stretching towards that specific spectrum. What other factors would be in play in this situation that would make it stretch towards a certain spectrum?


Don't know, since you said, "the plants tend to lean and grow towards the bluer of the light 6500 kelvin."

Phototropism, aka leaning, is caused by the elongation of the stem cells on the shady side of a stem which tilts it towards the light source. Without spectral output graphs and daily observations it's anybody's guess.


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## RickWhite (Feb 8, 2010)

madcatter said:


> I vegged a crop under LED's and they grew very well.... but when it comes to flower time, there is not near enough lumens and intensity.... so HID for the flowering stage for me for sure...


Yes, but on a watt per watt basis LEDs crush HID.


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## Natures Cure (Feb 9, 2010)

RickWhite said:


> Is there and reliable data on what is more beneficial to a plant?
> 
> It seems that my 250W Hortilux Blue MH with a 6500K temp is outperforming my 600W Hortilux HPS for vegitative growth.
> 
> It's hard to tell but I'm wondering if going with the 1000W 6500K MH for the entire grow isn't the way to go. Or maybe, the new ceramic MH bulbs.


Rick the only real answer to that is to mix your spectrums . . . ideally you can use 1 600w MH and 1 600w HPS.

the only downside is heat.

 &


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## figtree (Feb 9, 2010)

Uncle Ben said:


> Don't know, since you said, "the plants tend to lean and grow towards the bluer of the light 6500 kelvin."
> 
> Phototropism, aka leaning, is caused by the elongation of the stem cells on the shady side of a stem which tilts it towards the light source. Without spectral output graphs and daily observations it's anybody's guess.


Taking everything into consideration, and finding the only difference between the 2 light sources being the spectrum (color tempurature) wouldnt that tell you that it is the spectrum (color temp)? if there are no other variables, couldnt we use the scientific theory of hokums razor in this case? or would we just say its anybodies guess? and throw out our nightly observations.

UB, I'm not trying to dispute you by any means, i take your advice to heart. i am trying to grasp this theory of yours that spectrum is not important, am i reading you correctly?


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## Uncle Ben (Feb 9, 2010)

figtree said:


> UB, I'm not trying to dispute you by any means, i take your advice to heart. i am trying to grasp this theory of yours that spectrum is not important, am i reading you correctly?


No, you're not reading me correctly. I don't think getting anal about it and dealing in theories amounts to anything more than forum fodder. Mine is not theory, mine is real world application. "In theory", a 6500K lamp would produce less stretch being that it contains more blues.

Have you ever grown cannabis using a plain jane MH or HPS exclusively from start to finish? Yes or no?

BTW, I also studied photomorphogenesis to death. Check it out.

UB


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## RickWhite (Feb 9, 2010)

figtree said:


> Taking everything into consideration, and finding the only difference between the 2 light sources being the spectrum (color tempurature) wouldnt that tell you that it is the spectrum (color temp)? if there are no other variables, couldnt we use the scientific theory of hokums razor in this case? or would we just say its anybodies guess? and throw out our nightly observations.
> 
> UB, I'm not trying to dispute you by any means, i take your advice to heart. i am trying to grasp this theory of yours that spectrum is not important, am i reading you correctly?


WTF? Occam's razor isn't a scientific theory. More of a rule of thumb and sometimes a fallacy.

Plants are complex organisms and it is possible that a given wavelength of light could cause more photo-tropism than another without causing more over all growth.

In doing more research, I have found that the HPS bulbs do actually have better spectrums than the others in terms of PAR watts.

See, graphs can be very misleading. Especially given something this complex. What do you suppose those HPS spectrums would look like if we took out the tall yellow spike? They might actually look better.

For now, all we have is PAR watts and the HPS are proving to be best.


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## figtree (Feb 10, 2010)

Oops sorry guys, just trying to figure this stuff out. Guess i shouldnt medicate before i post.
UB again, not trying to dispute you at all. by no means.

I curently use hps.

I will step aside, cuz i have no idea. just trying to learn and use my observations, and bounce them off someone that has a greater understanding of it.
I will just watch this thread and learn from now on.
Peace, good luck on your grows yall.


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## figtree (Feb 10, 2010)

For Rick: I was refering to line #2
and your right its not a theory, its a principal...... sorry for being medicated.

Noun
Occam&#8217;s razor

1.The principle that entities should not be needlessly multiplied.

2.(sciences) The principle of preferring the simpler of two competing theories.

OK, now I'll just watch and keep my mouth shut!


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## Philip Burek (Jan 26, 2018)

FuZZyBUDz said:


> well a 1000 watt HPS kiks out like 140000 lummens but a a MH kiks out 100000, but with the HPS u will deffinately have sum dence buds, MH have a risk of a more airy buds with the less lummens, but u really got more potency out of the MH compared to the HPS.


 Ed Rosenthal's book will answer all your questions for 30 bucks. I learned from basically green to producing 21.5% thc .8% cbd. Sour Tangie Crocket's cut.


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## Philip Burek (Jan 26, 2018)

T.H.Cammo said:


> *Lumens Vs Spectrum*
> 
> 
> 
> ...


Plants use about10%


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## Philip Burek (Jan 30, 2018)

Lumens make a big difference when they are in the proper spectrum. Plants convert chlorophyll a-b & beta carotene into sugars/foods by absorbing light mostly from the red and blue spectrum. I use a 2100k 1000w Plantmax HPS with 8 T5 fluorescents 4-6500k and 4 hortilux UVA/UVB spectrum in a 5'.5" x 5'.5". The plants thrive and the buds drip...but lighting can be mixed with great results. I have never tried CMH... Just make sure you are getting UVB/UVB it does increase THC.


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## PhenoMenal (Jan 30, 2018)

Anyone have any thoughts on the spectrum that's output by the Samsung LM561C's white light LEDs used on quantum boards?





They have 2700k, 3000k, 3500k, 4000k, 5000k, 5700k, and 6500k, and output an impressive *200 lumens/watt* - i think only Samsung's LM301B's which were announced mid-2017 beat them in that regard at 220 lumens/watt [Samsung news link].

*The theoretical max for "a white LED with phosphorescence color mixing" is 260–300* lumens/watt [physorg src]. Fascinating tech race to a finish-line established by physics 

Quite stunning efficiency when compared to other well-known lights [img src]:





ps. ^ *Good thing incandescent lightbulbs are being banned/phased out* in many countries.

Anyway here's the 3000k and 6500k from the [LM561C datasheet]:






There's also very little infra-red above 700, so not much in the way of heat, and because they're outputting so many lumens per watt there isn't much being wasted as heat either, which i guess explains why most are just passively (and silently) cooled with heatsinks instead of active noisy fans, i'm guessing bedroom growers will no doubt appreciate the extra quietness


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