HPS vs. MH vs. Mixed Spectra - Page 4

*Cannabis Connoisseur* · 10-23-2002, 09:53 PM

This arguement is old. A quick look around the boards shows which light provides optimum results. HPS bulbs are not only more common among indoor grows(multi-bulb or not)...they truly are more efficient.

Mixed light *may* be more productive on some level...but yields are what we're here for. And it's the hps that puts out the yield....all my experience tells me that. I've grown under mh for about a year...then switched to an hps and nearly got 150% of my previous yields.

Why add another 400 watts of MH when 400 watts of HPS will give you more buds?

C.C.

*OzGrowa* · 10-24-2002, 02:32 AM

Quote:

Mixed light *may* be more productive on some level...but yields are what we're here for. And it's the hps that puts out the yield

I agree absolutley with this, Im also about potency, and by god if my bud was any more potent I wouldnt be happy smoking, it's almost toxic its so strong, I cannot possibly see how it could be stronger by the addition of different lamps, I have done MH and HPS grows and I experienced much lower yeilds than straight HPS alone. I also usually go to Amsterdam at least once a year so I smoke a wide menu, bio, organic from MH and HPS rooms, my bud can take the pepsi any day. I think ensthusiasm has run amok plain and simple.

It boils down to efficiency of lamps, the more lumens the better.

There is another thread that discussed UV and other combinations of lamps in some depth, as CC has mentioned its kind of an old issue around here for most of us.

anyways, Ill leave you to it

Oz

KRS_ONE · 10-25-2002, 02:47 PM

Just as humans need a balanced diet, plants need balanced, full-spectrum light for good health and optimum growth. The quality of light is as important as quantity. Plants are sensitive to a similar portion of the spectrum as is the human eye. This portion of the light spectrum is referred to as photosynthetically active radiation or PAR, namely about 400 to 700 nanometers in wavelength. Nevertheless, plant response within this region is very different from that of humans.

The human eye has a peak sensitivity in the yellow-green region, around 550 nanometers. This is the "optic yellow" color used for highly visible signs and objects. Plants, on the other hand, respond more effectively to red light and to blue light, the peak being in the red region at around 630 nanometers. The graphs below show the human eye response curve and the plant response curve. Note the vast difference in the contours.

In the same way fat provides the most efficient calories for humans, red light provides the most efficient food for plants. However, a plant illuminated only with red or orange light will fail to develop sufficient bulk. Leafy growth (vegetative growth) and bulk also require blue light. Many other complex processes are triggered by light required from different regions of the spectrum. The correct portion of the spectrum varies from species to species. However, the quantity of light needed for plant growth and health can be measured, assuming that all portions of the spectrum are adequately covered. Light for plants cannot, however, be measured with the same standards used to measure light for humans.

First, how do we measure light quantity for humans? The obvious way is based on how bright the source appears and how "well" the eye sees under the light. Since the human eye is particularly sensitive to yellow light, more weight is given to the yellow region of the spectrum and the contributions from blue and red light are largely discounted. This is the basis for rating the total amount of light emitted by a source in lumens.

The light emitted from the source is then distributed over the area to be illuminated. The illumination is measured in "lux", a measurement of how many lumens falls on each square meter of surface. An illumination of 1000 lux implies that 1000 lumens are falling on each square meter of surface. Similarly, "foot-candles" is the term for the measure of how many lumens are falling on each square foot of surface.

Clearly, both lumens and lux (or foot-candles) refer specifically to human vision and not to the way plants see light. "Lumens" is a meaningless term in the plant world.

Currently, there are [b]2 Basic Approaches to Developing a Light Rating for Plants...Measuring Energy, or Counting Photons

PAR

PAR Watts for Plants

Watts is an objective measure of energy being used or emitted by a lamp each second. Energy itself is measured in joules, and 1 joule per second is called a watt. A 100 watt incandescent bulb uses up 100 joules of electrical energy every second. How much light energy is it generating? About 6 joules per second or 6 watts, but the efficiency of the lamp is only 6%, a rather dismal number. The rest of the energy is dissipated mainly as heat. Modern discharge lamps like high pressure sodium (HPS) and metal halide convert (typically) 30% to 40% of the electrical energy into light. They are significantly more efficient than incandescent bulbs.

Since plants use energy between 400 and 700 nanometers and light in this region is called Photosynthetically Active Radiation or PAR, we could measure the total amount of energy emitted per second in this region and call it PAR watts. This is an objective measure in contrast to lumens which is a subjective measure since it is based on the response of the subjects (humans). PAR watts directly indicates how much light energy is available for plants to use in photosynthesis.

The output of a 400 watt incandescent bulb is about 25 watts of light, a 400 watt metal halide bulb emits about 140 watts of light. If PAR is considered to correspond more or less to the visible region, then a 400 watt metal halide lamp provides about 140 watts of PAR. A 400 watt HPS lamps has less PAR, typically 120 to 128 watts, but because the light is yellow it is rated at higher lumens (for the human eye).

"Illumination" for plants is measured in PAR watts per square meter. There is no specific name for this unit but it is referred to as "irradiance" and written, for example, as 25 watts/square meter or 25 w/m2.

Photons

Another means of measuring light quantity for plant growth involves the understanding that light is always emitted or absorbed in discrete packets called "photons." These packets or photons are the minimum units of energy transactions involving light. For example, if a certain photosynthetic reaction occurs through absorption of one photon of light, then it is sensible to determine how many photons are falling on the plant each second. Also, since only photons in the PAR region of the spectrum are active in creating photosynthesis, it makes sense to limit the count to PAR photons. A lamp could be rated on how many actual tiny photons it is emitting each second. At present no lamp manufacturer does this rating.

It is also possible to plot a curve showing the effectiveness of energy in different regions of the spectrum in producing photosynthesis. The fact that blue photons contain more energy than red photons would need to be taken into account, and the resulting curve could be programmed into photometry spheres to directly measure "plant lumens" of light sources instead of "human lumens." This is likely to happen at some point in the future.

The main ingredient in plants that is responsible for photosynthesis is chlorophyll. Some researchers extracted chlorophyll from plants and studied its response to different wavelengths of light, believing that this response would be identical to the photosynthetic response of plants. However, it is now known that other compounds (carotenoids and phycobilins) also result in photosynthesis. The plant response curve, therefore, is a complex summation of the responses of several pigments and is somewhat different for different plants. An average is generally used which represents most plants, although individual plants may vary by as much as 25% from this curve. While HPS and incandescent lamps are fixed in their spectral output, metal halide lamps are available in a broad range of color temperatures and spectral outputs. With this in mind, the discriminating grower can choose a lamp that provides the best spectral output for his specific needs.

Plants "see" light differently than human beings do. As a result, lumens, lux or footcandles should not be used to measure light for plant growth since they are measures used for human visibility. More correct measures for plants are PAR watts, PPF PAR and YPF PAR, although each in itself does not tell the whole story. In addition to quantity of light, considerations of quality are important, since plants use energy in different parts of the spectrum for critical processes.

http://www.venturelighting.com/Whats...ant_growth.htm

KRS_ONE · 10-25-2002, 02:49 PM

KRS_ONE · 10-25-2002, 02:53 PM

Can anyone honestly tell me why they feel HPS is more 'efficient' than MH???? NO, you cannot. If you try, you are either ignorant, stubborn, or kissing ass. If you still believe HPS is the better and the sole bulb necessary for plant growth, please give me some info, not a meaningless picture. Give me SOMETHING! PLEASE, OTHER THAN YOUR WEAK ASS EXPERIENCES.

Please, stop humiliating yourselves...btw I gave this thread 1 star because of all the ignorance.

Keep it Real.

*OzGrowa* · 10-25-2002, 03:29 PM

You are more than welcome to keep posting your charts and graphs that explain the principle of PAR and photonic emmisions KRS_ONE providing you remain within system rules. Your last message as well as being naieve, was inflamatory and unneccessarily hostiile. I was more than polite in my reply, I was confrontationsal as I allways am when someone posts what I believe to be complete rubbish.

I am concerned with growing high quality marijuana and doing so in the most efficient and productive way possible, I post the pictures to back my claims up, both on a small and large level and yes I feel great humiliation everytime I see people blindly following theory with no understanding of cannabis, environment, genetics or even lousy real world experience

whatsoever. From the small closet to the 40K operation, HPS is the only lamp you need.

Ill post some more of my '...weak ass experience...' meaningless pictures today for you

, unlike you my aim is growing plants, I dont have a garden full of theoretical papers to post pictures of

. I have multiple 10k ops and a 4k setup at my home, but I am sure that is weak ass compared to your level of experience and scale as your pictures will surely show us all.

Like I said before I am allways willing to learn, you have made some pretty wild claims KRS_ONE and I would love to see the results of your theory in action by you posting some pictures of your plants grown under MH/HPS or any other crackpot alternating light methodology.

Without us seeing what you can do, your claims are simply, theories.

grow hard,

OzGrowa

Anamist · 10-25-2002, 10:37 PM

Ozz-

You're makin a whole lotta sense. How? I don't know. You cite this tazawa study repititiously at the outset, and tell us how much proof of hps's efficiency this guy has made, and then never properly reference. Lo and behold, somebody digs it up, and it says the exact opposite of the point your trying to make. So now you ignore it and want 'proof in pictures.' Yeah, right.
Then you tell everyone to provide some real evidence. So, someone sends you to several places where tidbits of evidence, but evidence nonetheless, is. At this point, its the only evidence we all here have. If you ran a controlled study, lets see it instead of showing us some pictures my friend who just learned how to grow and happens to get a good phenotype and some decent advice could make. There is a little bit of evidence in Josehempseed's thread. Further, you assert that large ops don't use multispectrum systems, period, denying the pics supplied by Delta, and despite your problems with his methods, Krusty. Now, you might think its pretty big to have a 10K ops, but here in the US, those are relatively small operations. Some of these operations do use many different bulbs. And when you move to the legal market, it is common for nurseries to use a multi lighting system as well, wouldn't a massive nursery with literally hundreds of lights care the most about what is most effecient, even moreso than you and your little old 10k ops? Anyway, I apologize, I do not mean to insult your argument in and of itself, just your method of argumentation. I have not seen the results but intend too very soon cause I'm tired of all the bulls#%. You act as though this is an entire discussion to prove something to you. Others appear here in the interest of TRUTH.
I was not even argumentative last time, I simply pointed out that there are many pictures on the net of people with multispectrum ops. Yet you jumped on me like I was arguing with you when I didn't even take a position in the interest of a non-defensive dialogue. Defensiveness, at least here in the US, is almost the same as guilt or admission of NOT BEING TRUTHFUL.
Anyway, I'm talkin out my ass, here' s a nice chart from the Tazawa study that pretty much sums it up:

*Cannabis Connoisseur* · 10-25-2002, 11:07 PM

...that my opinion amounts to a "weak ass experience". It hurts real bad after I harvest my big, juicy, resinous buds. During the harvest, all I'm thinking about is how wrong I'm doing things. After I smoke the brain numbing scissor hash, I feel nothing but remorse. When I'm relaxing with a debhilitating indica, and I get that strong musty narcotic type taste from my smoke...I weep in terror for the upcoming generation of hps grown plants and how they will suffer.

I was intrigued by your PAR comments...but not convinced. Now, after your rather flaming post, your opinions hold little value to me. Also, practical experience is superior to theory everytime....you can teach someone to play the guitar , but if they've never played the instrument, they are basically useless when it comes right down to it. Do you have a MJ garden of your own?

***As an extra thought..KRS, take a look at my garden link. Would my flower cab be a suitable place to try a mixed light experiment that would help satisfy you? The two middle flats would receive a well mixed blend. If we're going to do this it needs to be soon...I'm about 5-6 days from putting the next cycle into veg.***

C.C.

KRS_ONE · 10-26-2002, 12:17 AM

Oh yeah, more deceitful actions by the 'asst administrator'...

OzGrowa: I am wondering...Why did you purposely put fake links on this thread?

Look at this post from page 2 of this thread...

http://www.hempcultivation.com/420/s...awa#post244104

Now, look at the "online references" thread at the top of this forum. In July, Oz CLEARLY had valid links to the Tazawa studies. Yet he PURPOSELY fudged the links because they did not back up his claims, after he said they did!!!

http://www.hempcultivation.com/420/s...awa#post186559

iknoublo · 10-26-2002, 01:13 AM

From what I can tell, I seems that the people soley interested in production are pro hps. The people willing to provide the multi bulb system are more interested in the absolute quality. I am subscribing to this thread only because it interests me, and since I am not a commercial grower I would add the lights to get a superior plant.

On a side note~ If I am getting this correct, in order to truly weigh the results, one would have to trim the buds from the stem. Since it appears the hps stem would be elongated and thus would weigh more. I may be thinking to deeply, so excuse me if I sound weird.

Oz, production & electric bills set aside, is it possible to get a better plant using multiple lights? Which I would not mind adding, for a tighter, better bud btw.

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