# Thoughts regarding Wattage effecting yield and potency, let's apply it to Vert!



## slamsomethc (Dec 16, 2013)

https://docs.google.com/file/d/0ByW-RytTeYMQMTc3M2MxYzMtNjUxZi00ZGZhLTg0YWMtYjAzMzNjNGY5NDEw/edit

I will quote the abstract from the article and sum up what I can interpret from it.



> "The floral development and potencies [&#916;(9) -tetrahydrocannabinol (THC) contents] of cannabis plants were compared when grown indoors under high-pressure sodium lamps consuming electrical power at three densities (270, 400, and 600 W/m(2)). After a 3-week vegetative phase, plants were grown for 8 weeks, with lamps maintaining an artificial day length of 12 h. Foliar and floral yields were measured. Gas chromatography was used to measure the content of the psychoactive cannabinoid THC. Mean yields per unit of electrical power in each lighting regime ranged from 0.9 to 1.6 g/W, the highest being achieved in the lowest irradiance regime. The individual potencies of the separated leaf and flower materials were not affected by increasing irradiance. However, there was a corresponding increase in the overall potency of the aerial plant tissue. This was because of the plants in brighter conditions producing a higher proportion of floral material.


*TL;DR*
Plants were grown at 270, 400, and 600W/square meter. 3 week veg, 8 flower. THC production in flowers was identical for all scenarios, but the lower wattage plants showed improved gram/watt yields (CHECK OUT THE GRAPH ON PAGE 3 SHOWING WHITE BERRY ). The leaves in higher wattage grows produced more THC, because there were more flowers to leaves produced on those plants. 

From what I gather, that would mean perfect trim for hash from the high watt runs, higher yield g/W yield in lower wattage set ups, the higher wattage runs, while not producing as great g/W data, do produce more plant material overall, likely from the area it can cover; all these things noted observations are ones that most growers here are quite familiar with. I wish that photos were included so that we would be able to view the calyx to leaf ratios, and size of the fan leaves on each wattage grow as that last tidbit of info in the abstract is quite interesting.

All this being said, has anyone ever previously read this, taken it into account and went with swapping out for instance 2 1000W set ups for 5 400Ws? I'm really interested in finding data regarding g/W yields, overall g yield, and time spent on the grow overall. I wonder what others think when posed the following question: Would it be worthwhile to swap out for more numerous smaller bulbs? Vert grows in particular can take advantage of short light to canopy distances and still cover quite an area, so I really wonder if it would be worth the effort to do so.

Maybe I'll just have to do some testing myself. I run 1200-1800W (600W's) typically, and have just recently began growing vertically my last several grows. I wish I had the capacity to afford simultaneously running 2400W (3 400W's and 2 600W's) in similar areas, or attempt to match (it would require some arithmetic to account for not growing flat) the square meters noted in the above study.


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## qwizoking (Dec 16, 2013)

I don't know but its clear they know nothing of growing weed..on one line they say a sea of green style plant averages 33grams or whatever and that number jumps 800 grams simply because the plants weren't as close............ lol. Veg time definitely wasn't the real reason

After reading further........malarky


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## slamsomethc (Dec 16, 2013)

Not to be defensive, as I couldn't care less how pro these researchers are, but their intent is to look at one effect upon yield, which is based upon conflicting reports in their source of knowledge. They only present this widely varying data as cited material from other sources, and they do note that the numbers as high as 800g/plant could be from including trim. I just don't think this article should be disregarded for something like that, but at the same time do not believe it is the end-all statement (as none should when ready ANY scientific material, yet many stand by their first found/accepted piece of information regardless of additional information)

I don't think they suggest that as the only cause (plants being further spaced out to allow for larger growth) for increased yield per plant, nor do they claim that varying vegetative lengths had nothing to do with the difference. I believe they use those conflicting examples early in their text to note that judicial systems' determination of yield per grow is highly skewed as those systems really have no way of accurately accounting for the things us growers do when predicting yields. Their intent is to remedy this confusion in our governments, though unfortunately it seems for the intent of more accurately prosecuting growers for their operation size.

It definitely is worth noting that their measure of light is not what most of us measure by. From what I gather, they use a combination of 1000W and 250W bulbs near one another to create their measurements of 270, 400, and 600W/square meter. So, I imagine the single 250 covered 0.9259 square meters, or 3.04' square, on it's own being quite low, and the 1000W covered 1.666 square meters, or 5.45'x5.45', only assuming that their highest range (600W/meter), which would be their 1000W bulb being used, and maybe 2 250W covering 1.25 square meters. I am not sure as they only say,


> By using contrasting densities of 250 and 1000 W Philips SON-T high-pressure sodium lamps (Philips Lighting UK, Guildford, Surrey, U.K.), three distinct zones were established within which the rates of electrical power consumption were 270, 400, and 600 W&#8260;m2.


So, all that being said, I have some questions as I've never bothered to educate myself on 250W lights and such very much. What are some growers' recommended distances from canopy for 250W HPS bulbs for optimum growth? I imagine for one 250W to cover 3'x3' would be quite a bit taller than many would prefer, even if it were a bare bulb. Also, my math was done using quite a few assumptions as again the only state that they using varying numbers of 250/1000W bulbs; I'm curious if others agree that the "400W/m2" number would be achieved from 500W in an area slightly larger than 1 meter.

Thanks for the opinions and input in advance you guys!


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## qwizoking (Dec 16, 2013)

Well they specifically say that "the disparity in average plant weight between the studies would have been attributed to the marked difference in plant density as the yield of cannabis plants is greatly effected by the number grown per unit area"....they then say "arguably therefore" as if using that to verify another unsubstantiated claim...
I can find many issues like above with that article....Now when a plant stretches for light it focuses on stem production to get closer. Yield is not improved but hindered and yes thc is not increased as the ratios remain the same but ratio of total per weight will improve...

Note the gw on bottom?? Lol no wonder



Anyway sun throws avg of 7k lumens per sqft..they don't use watts so throw that out the window....10k is sun Max and will bleach 5k min for decent bud


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## slamsomethc (Dec 16, 2013)

> *Now when a plant stretches for light it focuses on stem production to get closer. Yield is not improved but hindered and yes thc is not increased as the ratios remain the same but ratio of total per weight will improve...*


Not an accusatory question or anything; Are you talking about their claim of increased weight (not weight per watt though) using the higher intensity lights?

I definitely agree that (surprisingly, as they mention veg/flower time for THEIR plants) they seem to overlook the importance of veg time as a key factor in the plant yield. Again, I suspect that this was written for a different audience and even go as far to say that some involved in the study may not be the happiest about the way it was presented. Think of the intent of this article again, to help government agencies more accurately calculate grow potential for "appropriate" convictions.


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## qwizoking (Dec 16, 2013)

Yea they said they got more weight off less lumens but say more lumens increase flower weight.....now I know I don't smoke stems so what were they weighing? 
I saw gw pharmaceuticals after I found the article sketchy..just giving my 2¢


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## slamsomethc (Dec 16, 2013)

They are saying that the yield per watt is improved for their lower intensity light test grows, while the larger ones covering a larger area (and maybe at the distances they had the lights less power in light, again more missing data in this study) produced more overall amount of buds, but NOT more per watt

Arbitrary numbers here for an idea.

Let's say a 250W set up they had produced 2g/W. Yeah, 500g, or almost 1 1/8 pounds off one 250 light for just shy of a meter squared, or 2 250W's at about 1.9 meters squared, which is quite some height for 250W lights to cover SUUUURE, even for that white berry. Their lowest g per W for a strain was just over 1 even, so a median of about 1.5 or higher looks consistent according TO THEIR graph.

Anyway, so their 250W system produces great g/W, but they have a 1000 or even 2000W set up covering 1.66 meters or 3.33 meters squared respectively that produces oh let's say 800 or 1600 grams (again, respectively to 1000/2000W). 800g/1000W vs 500g/250W. More overall but less in ratio.


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## slamsomethc (Dec 16, 2013)

Also, sorry to double post, but I'm unsure of the connotations regarding GW Pharmaceuticals. I know they make Sativex (cannabis based treatment for MS), but what would you say the benefits of this article would be for them? Again, no accusations from me, I'm a simple curious conversationalist that desires remedies to moments of ignorance. 

To ensure the government keeps it illegal so they can sell their pharms?


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## NorthofEngland (Dec 16, 2013)

Quote "All this being said, has anyone ever previously read this, and taken it into account, *swapping out for instance 2 1000W set ups for 5 400Ws?* I'm really interested in finding data regarding g/W yields, overall g yield, and time spent on the grow overall. I wonder what others think when posed the following question: Would it be worthwhile to swap out for more numerous smaller bulbs? Vert grows in particular can take advantage of short light to canopy distances and still cover quite an area, so I really wonder if it would be worth the effort to do so".

I am a little confused by your mentioning swapping 2 x 1000w for 5 x 400w. Both result in 2000w....
The study is about intensity of watts per area...Yes?
Not about using different sized lamps to compare yields using the same wattage intensity....?

Or am I missing something?

(Disclaimer: At this point I need to point out that I am new to growing and much of the thread taxed my knowledge to its outer limits).


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## slamsomethc (Dec 16, 2013)

Hey there, Northerner!

Sorry for the confusion, but that article states (check out the link, and their graph on page 3) that their lower light intensity grows yielded better per watt, so that being said I'm curious if others have found this to be true, find it worth the savings in electricity (again, thinking of earning 3000-4000g(6.6-8.8 lbs)/2000W versus 1500-2500g(3.3-5.5lbs)/2000W.), and just find it worthwhile in any way to go with the same wattage produced through more numerous but lower intensity bulbs, vs less but higher intensity bulbs. 

The study does cover watts per area, but I would not be growing in the same area I suspect them to have for the light density I calculate.

I assume lights used based on the fact that other combinations would be ridiculous (270W/m2 using one 1000W is a coverage of 12 friggin square feet, WTF LOL)

I can imagine in a SOG where one is not concerned about light penetration, lower watt bulbs could be very beneficial, but I'd like to be proven right/wrong for good, or at least have some good insight into it without spending 4-12 months figuring this out on my own, though I probably will at some point anyway as control experiments are so much fun when involving cannabis.


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## NorthofEngland (Dec 16, 2013)

This is assumption, on my part, but I would think that running 2000w (5 x 400w lamps) used more energy than running 2000w (2 x 1000w lamps). ???
5 Ballasts and 5 bulbs as opposed to 2 and 2.
Efficiency would be compromised.

Plus this entire study was carried out with the intention of simplifying prosecutions.
Most indoor growers use the 400/600w set ups.

Are they now to be considered more prolific cultivators than the growers who use the big, professional 1000w systems?

The laws governing Cannabis are such bullshit!


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## slamsomethc (Dec 18, 2013)

That is true. Ballasts consume power at the same rate/wattage as their specified lights, right? If so, efficiency just got thrown out the window; I'll stick with a vertical SOG using 2 600 HPS bulbs in a 4'Wx5'Lx5.5'H (potential max canopy specs; box is about 1ft larger on each dimension to accomodate) area. I'm really trying to begin ensuring I am consciously accountable for my exact overhead costs per gram/ounce/whatever by reducing overall expenses and recording/tracking them more accurately/consistently.


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## qwizoking (Dec 18, 2013)

Last I calculated I was at 37¢ per gram..I'm pretty happy about that
If I was running indicas or hybrids and able to throw another harvest per year I could cut that about 9¢
(That's including all yearly costs, bills bulbs, nutes)


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## jarvild (Dec 18, 2013)

I use to run a 430 and a 400 in my 2.5' x5' bloom room recently switched to a single 600 and it made my flowers denser and increased my yields by 25%. So I don't see how they can claim that.


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## slamsomethc (Dec 18, 2013)

Nice! Overall g's, not just g/W, yeah? What bulb ran at 430? 

Also, may I ask what were your yields per 830 watts? I don't want to prove your wrong, I'd just like to know if my assumptions are incorrect or not, and could show evidence that could discredit their info IF your veg time was similar. It'd be nice to see an actual grower replicate their study to BS them or not.

For instance: let's say your 830 watts produced 500 grams, just over a pound, which is ~.6g/W. You say you increased your yield 25% (assuming you mean overall yield), which would mean dropping down to one 600W would produce 625g for you which is ~1.04g/W. An increase in g/W AND overall g production. Very nice, but would discredit their study -once again - IF your veg was ~3 weeks. 

Qwizo, that's good to hear; glad that it sounds as I won't be hitting myself as bad as I planned for. I do always plan conservatively though and expect the worst prices to fall upon me so that when I'm running smoother than expected I'm quite happy, lol


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## jarvild (Dec 19, 2013)

slamsomethc said:


> Nice! Overall g's, not just g/W, yeah? What bulb ran at 430?
> 
> Also, may I ask what were your yields per 830 watts? I don't want to prove your wrong, I'd just like to know if my assumptions are incorrect or not, and could show evidence that could discredit their info IF your veg time was similar. It'd be nice to see an actual grower replicate their study to BS them or not.
> 
> ...


Its an old sun system 430 watt ballast with a 430 watt plant max bulb, Can't really tell you overall yield as I grow perpetual, 2 plants every 2 weeks, but I can say my per plant yield went from 3 1/4 to 4 and over .


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## Nizza (Dec 19, 2013)

hey jarvid i have a 430w , is there anyway to tell if the ballast is bad? the light (hortlux) doesn't seem super bright compared to a friends regular hps (same wattage)

as for lights, i look at the lighting outputs in lumens for all the bulbs and the lumen to watt ratio DECREASES after 600 watts. 400's and 600's being better ratios than 1000's

as for potency and 1000's, it could be that the other lights are too close and creating heat and the 1000w is further back, degrading overall less THC 

just a few of my thoughts hope others can chime in


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## slamsomethc (Dec 19, 2013)

Definitely true that those bulbs are much more efficient at the wattage they run.

I wish I had the capacity to run identical grows, save one variable: the area covered by the light. It'd be very interesting to know several strains' ability to produce (or not produce) at certain w/m2 and height bulb. I really would like some hard data regarding the variables responsible for accurately measured diminishing returns on yield/watt. I know I always saw figures (for flat grows with reflectors) of anywhere between 50-75w/ft2, but it would be amazing to discover this for vert where the bulbs lumen output is being spread all around rather than partially redirected on a smaller focused area.

From the study I posted I would gather that many could increase the diameter of their vert set ups and play around with it to find the sweet spot where they produce the max g/w, as they state the w/m2 decreasing aided yield. 

Maybe this is a chance to make myself known around here  I've always documented grows very well for our own knowledge, maybe it's time to put the macro lens and DSLR to work for public data.


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## jarvild (Dec 20, 2013)

Nizza said:


> hey jarvid i have a 430w , is there anyway to tell if the ballast is bad? the light (hortlux) doesn't seem super bright compared to a friends regular hps (same wattage)
> 
> as for lights, i look at the lighting outputs in lumens for all the bulbs and the lumen to watt ratio DECREASES after 600 watts. 400's and 600's being better ratios than 1000's
> 
> ...


Your capacitor is more than likely getting weak. I had to replace mine last year.


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## comercial (Sep 4, 2014)

slamsomethc said:


> Not to be defensive, as I couldn't care less how pro these researchers are, but their intent is to look at one effect upon yield, which is based upon conflicting reports in their source of knowledge. They only present this widely varying data as cited material from other sources, and they do note that the numbers as high as 800g/plant could be from including trim. I just don't think this article should be disregarded for something like that, but at the same time do not believe it is the end-all statement (as none should when ready ANY scientific material, yet many stand by their first found/accepted piece of information regardless of additional information)
> 
> I don't think they suggest that as the only cause (plants being further spaced out to allow for larger growth) for increased yield per plant, nor do they claim that varying vegetative lengths had nothing to do with the difference. I believe they use those conflicting examples early in their text to note that judicial systems' determination of yield per grow is highly skewed as those systems really have no way of accurately accounting for the things us growers do when predicting yields. Their intent is to remedy this confusion in our governments, though unfortunately it seems for the intent of more accurately prosecuting growers for their operation size.
> 
> ...


I think you will find it really hard to grow trees. With those low wattage bulbs. They lack the light "punch" needed for thoural penetration. That being said, I'm looking forward to this thread.


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## ttystikk (Sep 6, 2014)

I'm running vertical bare bulb with several bulbs at several wattages. This was a good read and confirms my suspicions that plants can indeed respond well to many lighting regimes.


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