CMH / QB288 / QB120 / SB240 / VERO 29C comparison...

CobKits

CobKits

Well-Known Member
if you wanted to compare it to cobs in the case of citizen (who has handy info on their arrays right in the part number)

for 1212 gen6s on a thin slate-style heatsink vs quantum boards you need about twice the # of diodes

1212= 144 diodes

so to match your 720 diode array in efficacy youd need 1440 diodes, or 10 chips

so an array of 9 1212s is gonna be pretty close to the 6 qb120s so you should compare that on cost. pin fins cost more but will also bump chip efficiency

there is no wrong answer. any of the solutions you posted since post 1 will grow great bud efficiently. youre racking your brain to get the last few percent when you need to be focusing on getting your strains up over 80% of their potential with all the other factors other than light efficacy
 
U

Unagi

Active Member
@CobKits thanks for teaching us noobs, we are lucky to have folks like you here to guide us.

You make a really good point with getting the rest of the growroom to run more efficient before focusing on a 2% boost from light efficiency. Huge eye opener for me!
 
ganjamystic

ganjamystic

Well-Known Member
CobKits said:
so an array of 9 1212s is gonna be pretty close to the 6 qb120s so you should compare that on cost. pin fins cost more but will also bump chip efficiency
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awesome. thank you. I'lm going to look into this.
CobKits said:
there is no wrong answer. any of the solutions you posted since post 1 will grow great bud efficiently. youre racking your brain to get the last few percent when you need to be focusing on getting your strains up over 80% of their potential with all the other factors other than light efficacy
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word. I tend to overthink as you may have noticed. you do have this maybe a little backwards though.. I've had my strains (and the species in general) as well as the other factors (environment, media, nutes, methods, etc) pretty well dialed for a while now, so that frees me up to focus on light efficacy ;) ... haha jk I strive to be constantly learning and improving of course... I feel like I've 'grown' as a grower with each and every round over over the years, and hopefully I will be better a year from now than I am now... that being said, for the last couple of years especially, I really do feel like I'm getting as much from my space as is possible without going to some type of vertical or stacked setup... and quality is pretty up there as well :weed:...

speaking of vertical stacked setups, check this out.. let me know your opinion.. you too, @Growmau5 ... to me, this looks like about the most efficient use of led and total cubic feet of growing space, not just area, that I can imagine... I also have an erie feeling whoever started this company was likely 'inspired' by this and other led growing forums, and decided to capitalize....
 
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ganjamystic

ganjamystic

Well-Known Member
Unagi said:
@CobKits thanks for teaching us noobs, we are lucky to have folks like you here to guide us!
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yes we are lucky! but speak for yourself ;) haha I may be new to diy and the technical side of all this but I'm no noob! haha not new to led (rocking blurples since 2010 :hump:) or growing :leaf: (since '04) anyway
 
U

Unagi

Active Member
You are right, i shouldnt assume you were a fellow noob :-)

Im just gratefull we have the option of many detailed reports on diffrent lights. When i first got into growing hps was the way to go, most of what I read about led (wich was blurples at the time) were really bad stuff. That mentality can linger and blossom when there is lack of information.

Rollitup community has definetly been a big part of the change in led tech from what I can tell. By steering people away from blurples, manufacturers are forced to keep up with the top end led. All this because we now have the right information available, and people to guide us so we can understand and digest it aswell :-)
 
tomate

tomate

Well-Known Member
Unagi said:
Rollitup community has definetly been a big part of the change in led tech from what I can tell. By steering people away from blurples, manufacturers are forced to keep up with the top end led. All this because we now have the right information available, and people to guide us so we can understand and digest it aswell :-)
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And all this thanks to @alesh 's his explanation of the math behind and many other users like @stardustsailor , @SupraSPL , @Growmau5 and some others...
 
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mcnasty_nug

mcnasty_nug

Well-Known Member
CobKits said:
there is no wrong answer. any of the solutions you posted since post 1 will grow great bud efficiently. youre racking your brain to get the last few percent when you need to be focusing on getting your strains up over 80% of their potential with all the other factors other than light efficacy
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This 100%. I did the same thing for weeks. Made posts and researched like crazy which cob is better, CMH or LED, oh wait quantum and chilled! ect ect. I ended up realizing all of them are fantastic ways to go. I already have a tent with 2 315CMH in em, so I went the most economic route. I'm building cxm-22 lights pushing them at about 75w each. Because all the rest was me spending like 2x the $$$ for how much benefit? Likely nothing because I can't grow that good! So yeah, throw together whatever you can best afford and manage, I highly doubt you'll be disappointed.
 
Danielson999

Danielson999

Well-Known Member
Sorry OP that I can't give you those numbers. I know that's all you came here for and got 5 pages of "they're all great!!" instead. Perhaps if you do find out the info you came here for you could post it for all of us to sort through also. Thanks!
 
ganjamystic

ganjamystic

Well-Known Member
OneHitDone said:
Lumens are for humans, I bet your plants are craving some of that Broad Spectrum CMH UV goodness :hump:
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higher lm/w = higher efficacy... in other words, more light for every watt you pay for... we're talking about full spectrum white light, so more lumens per watt means more PAR watts too.. you can use this calculator to convert lumens to lux, and this conversion chart to convert lux to ppfd... as far as UV, I have never seen any benefit personally, though your experience may be different.. I grew with only hps and t5 for 7 years, grew with both led and hps for several years, and have grown exclusively with led for the past several years. I've also grow outdoors in full sun... the best quality bud I've ever grown has been with led, hands down... part of that has to do with continually improving as a grower over the years, but certainly if led was lacking anything that plants crave spectrum-wise, there's no way I'd have been able to grow such healthy, frosty, potent nugs...

these buds don't look like they were craving anything they weren't getting, do they?


 
CobKits

CobKits

Well-Known Member
Unagi said:
@CobKits thanks for teaching us noobs, we are lucky to have folks like you here to guide us.

You make a really good point with getting the rest of the growroom to run more efficient before focusing on a 2% boost from light efficiency. Huge eye opener for me!
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if you have the ability, switching your drivers from 120 to 240V input is usually an easy 2-3% boost
 
Danielson999

Danielson999

Well-Known Member
ganjamystic said:
higher lm/w = higher efficacy... in other words, more light for every watt you pay for... we're talking about full spectrum white light, so more lumens per watt means more PAR watts too.. you can use this calculator to convert lumens to lux, and this conversion chart to convert lux to ppfd... as far as UV, I have never seen any benefit personally, though your experience may be different.. I grew with only hps and t5 for 7 years, grew with both led and hps for several years, and have grown exclusively with led for the past several years. I've also grow outdoors in full sun... the best quality bud I've ever grown has been with led, hands down... part of that has to do with continually improving as a grower over the years, but certainly if led was lacking anything that plants crave spectrum-wise, there's no way I'd have been able to grow such healthy, frosty, potent nugs...

these buds don't look like they were craving anything they weren't getting, do they?


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Lumens/watt is very basic though. What good are lumens a watt when some of the lumens are useless to a plant? My 1750K cobs are horrible lumens/watt but they do nothing but whisper sweet nothings into my ladies ear all day long. They're probably 95lumens/watt or so.

Anyway, if you want to judge a lights value for growing herb you'd be better off using umol/j measurement.
 
NugHeuser

NugHeuser

Well-Known Member
OneHitDone said:
Wouldn't this be 650.6ppfd for the 315CMH in a 3x3?

https://www.growersc.com/315w-3k-r

540ppf / .83 M² = 650.6ppfd
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I just ordered a par meter today and going to test my 630 watt double ended cmh. https://growershouse.com/growers-choice-horticultural-lighting-630w-de-cmh-complete-fixture?amp=1

Have only had it a few weeks and only in use about a week but my young plant has took off like a rocket ever since I switched it from 250 watts of blurple to the cmh. First 4 weeks were under the blurple.

I'm trying to decide on either 2 more 630s, 4 315s or investing in cobs. Im leaning towards the cmh's though. I dont need the most efficient lights in the world, I'm reading lots of good things about these cmh's and so far liking mine.
The light also runs cooler than my 600 watt hps(open hood).
This par meter will help me make my desicion though. I'm working with a 4x9'10"

I'll post the results I get.
 
ganjamystic

ganjamystic

Well-Known Member
Danielson999 said:
Lumens/watt is very basic though. What good are lumens a watt when some of the lumens are useless to a plant? My 1750K cobs are horrible lumens/watt but they do nothing but whisper sweet nothings into my ladies ear all day long. They're probably 95lumens/watt or so.

Anyway, if you want to judge a lights value for growing herb you'd be better off using umol/j measurement.
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I completely understand what you and @OneHitDone are saying. "lumens are for humans".. it's measure of the amount of visible light.. it's not the best metric to compare growlights.. µmol/J is better... totally get it.

that being said, if you already know the spectrum of a given light source is a good one for growing plants, then you also know higher lm/w of that light is going to mean more PAR watts too, right?.. and if you know the lumens and the area of the space you're trying to light, then you know the lux, and if you know the lux you can use these conversion factors to calculate PPFD.... so it's not like lumens and lm/w are irrelevant, especially with cobs, strips etc which aren't manufactured or sold as grow lights specifically. the manufacturer's test the lumen output and lm/w with a given set of test parameters, and publish that data... but cree and bridgelux and samsung, etc aren't publishing PAR and PPFD as far as I know..
 
Danielson999

Danielson999

Well-Known Member
You're right, lumen/w is not irrelevant. You can use a light meter that uses lm/w to balance out your hot spots or get a rough estimate of how powerful a light may be, especially if you know it's already tailored towards plant growth.
 
ganjamystic

ganjamystic

Well-Known Member
I did just notice there aren't conversion factors on that page for led.. just for fluorescent, hps, de hps, mh, and cmh... so even though the PPFD of 315 watts of 110lm/w cmh in a given area can be estimated by using that chart, the only way to know how that compares to the PPFD of 315 watts of 150+lm/w led in the same area would be to actually test with a PAR meter I guess...
 
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