Mau5Capades: builds & grow journal

alesh

Well-Known Member
Return does drop off drastically above 1000 PPFD, and water usage goes way up. But yeah, g/kWh does make more sense. Unfortunately, PAR meters are rather pricey so everybody can't just go get one. We need a cheap Chinese PAR meter for $20, like a little pen type thing that only reads PAR. Whoever invents one makes millions from the Cannabis industry. How hard could it be? I've seen iPhone apps that turn the phone into a lux meter, though probably a crappy one. Actually, if you have a lux meter you could convert to PAR with fair accuracy by using the conversion factor for cool white fluorescent, 74 or warm white, 76. Probably close enough.
The conversion factor is quite easy to determine if you know SPD of a light source.
PPFD [µmol/s/m^2] = illuminance [lux] / (LER [lm/W] / QER [µmol/J])
with LER/QER being the conversion factor

Ie 3000K/80CRI CXB spectrum:
PPFD = illuminance / (325 / 4.87) = illuminance / 66.735

edit: illuminance is what you measure with a luxmeter
 

alesh

Well-Known Member
No they wouldn't use G/W...A smart investor would use G/kWh. The other guy just went broke. G/kWh factors in time of use...which is what you pay for. As well as veg time and useage. G/w does none of that. It is a incorrect and misleading figure.

Exactly. Listen to what has been said for 40+years. 700-1000umols. This is no secret and plant don't give 2 shits where light came from and ,for all intents and purposes, what color it's in. Supply the quanta and get the results. G/kWh is how you supply quanta...not g/w.
Seems to me that Americans tend to use higher PPFD than most people in Europe. It also occurs to me that Americans are much more sativa oriented. Do sativas require higher PPFD?
 

BobCajun

Well-Known Member
The conversion factor is quite easy to determine if you know SPD of a light source.
PPFD [µmol/s/m^2] = illuminance [lux] / (LER [lm/W] / QER [µmol/J])
with LER/QER being the conversion factor

Ie 3000K/80CRI CXB spectrum:
PPFD = illuminance / (325 / 4.87) = illuminance / 66.735

edit: illuminance is what you measure with a luxmeter
It appears that about 400w of cobs per meter at 100 lm/w (40000 lux) would be about 600 PPFD then. For 1000 you're probably looking at about 600w per meter, ironically just like the standard HPS recommendation.
 

BobCajun

Well-Known Member
Basically yes. I wouldn't recommend to replace a HPS with a 100 lm/W LED, though.
Yeah but that's what the CXB cobs are, if you buy stock high bays. They drive 12 of them at 220v and 1049 ma. It's the small cobs, about 3/4" diameter. It definitely performs better than equal wattage of HPS. It's not the lm/w that really matters, it's what spectrum those lumens are composed of and whether they are being produced steadily by a DC power supply or quickly strobing on AC like HIDs do.
 

alesh

Well-Known Member
Yeah but that's what the CXB cobs are, if you buy stock high bays. They drive 12 of them at 220v and 1049 ma. It's the small cobs, about 3/4" diameter. It definitely performs better than equal wattage of HPS. It's not the lm/w that really matters, it's what spectrum those lumens are composed of and whether they are being produced steadily by a DC power supply or quickly strobing on AC like HIDs do.
That's why I don't use stock high bay lighting for growing.
 

Growmau5

Well-Known Member
Seems to me that Americans tend to use higher PPFD than most people in Europe. It also occurs to me that Americans are much more sativa oriented. Do sativas require higher PPFD?
This is an interesting statement & quite true from my observations. Seems backwards that we blast our rooms when space in so abundant here (generally speaking). While in Europe, they are more conservative in PPFD when space is more expensive and more limited.
 

sethimus

Well-Known Member
Yeah but that's what the CXB cobs are, if you buy stock high bays. They drive 12 of them at 220v and 1049 ma. It's the small cobs, about 3/4" diameter. It definitely performs better than equal wattage of HPS. It's not the lm/w that really matters, it's what spectrum those lumens are composed of and whether they are being produced steadily by a DC power supply or quickly strobing on AC like HIDs do.
and WHO uses them for growing?
 

BobCajun

Well-Known Member
and WHO uses them for growing?
People who don't want to have to mess around building electrical equipment. I went for the off-the-shelf solution. It's working perfect though, and no noisy fans. One 12 cob CXB high bay is just right for a 3'x1.5' cab. You just put the whole unit on top of the cab with a hole cut. All the heat is outside the cab. The aluminum reflector aids the main heatsink by acting as more surface area.
 

robincnn

Well-Known Member
This is an interesting statement & quite true from my observations. Seems backwards that we blast our rooms when space in so abundant here (generally speaking). While in Europe, they are more conservative in PPFD when space is more expensive and more limited.
I think power is cheaper in US compared to Europe
Or maybe Americans like big trucks, big roads, big grow lights and big buds.
 

bassman999

Well-Known Member
I think power is cheaper in US compared to Europe
Or maybe Americans like big trucks, big roads, big grow lights and big buds.
You forgot big boobs and butts!
America is the land of excess and waste.
Hummers and Corvettes etc...
I should know being american lol.

I agree with the idea of maximizing the small space like mine (2'x4') (.6x1.3M?)
with slightly diminishing returns if yield size is needed and space is non existent
 

Greengenes707

Well-Known Member
@alesh
Neither America or Europe decided what the plants want...the plants did.
One area is listening to their plants more than others imo. Again...if you not into diminishing returns...you're not maximizing the crop.
"If you ain't first, your last"...is defiantly an American mentality...but still valid for almost any industry or product.


@BobCajun we have far surpassed anything the general commercial lighting industry could produce. The way we run our chips is a complete waste according to Cree...because they only understand lumens and human percetion...not photons that plants actually use. We are hitting 170+lm/w....but more importantly means 2.5umols+/w. That is an output nothing can touch. And though it cost more to the maker...they are actually available for a few companies for more competitive prices than any commercial lighting company.
 
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Stephenj37826

Well-Known Member
Seems to me that Americans tend to use higher PPFD than most people in Europe. It also occurs to me that Americans are much more sativa oriented. Do sativas require higher PPFD?

Yes equatorial type plants require higher ppfd. The wider leaved varieties don't require as much light and is evident when they hit light saturation (when the leaves are droopy even though the Lights are still on for an hour or more). Notice the skinny leaved types don't seem to do this quite as frequently.
 

nogod_

Well-Known Member
GG you seem to be in the know when it comes to the commercial lighting industry.....to the best of your knowledge do Cree/Bridgelux/Citizen/Nicchia/et al even consider grow lights as a market?

I miss the regular updates on the C.O.B.S.S.L. thread :cry:


@alesh
Neither America or Europe decided what the plants want...the plants did.
One area is listening to their plants more than others imo. Again...if you not into diminishing returns...you're not maximizing the crop.
"If you ain't first, your last"...is defiantly an American mentality...but still valid do almost any industry or product.


@BobCajun we have far surpassed anything the general commercial lighting industry could produce. The way we run our chips is a complete waste according to Cree...because they only understand lumens...not photons that plants actually use. We are hitting 170+lm/w....but more importantly means 2.5umols+/w. That is an output nothing can touch. And though it cost more to he maker...they are actually available for a few companies for more comet iric prices than any commercial lighting company.
 

SupraSPL

Well-Known Member
I have experimented flowering with lower ranges of PPFD and did not see any noticeable major gain in gpw. On top of that, even if there was a gain I do not believe it would be worth it. What ends up happening the buds get very frosty but leafy and loose, hardly worth trimming and as GG pointed out, a poor use of space.
DSC09081a low ppfd.jpg DSC09084a low PPFD.jpg
 

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Rahz

Well-Known Member
I recently grew some tight nugs in soil under 500 PPFD. They weren't as frosty as my 800 PPFD hydro space. Total opposite, go figure. I did notice that the GPW wasn't super impressive (1.1 GPW), but as I generally hydro I don't have a direct comparison yet under LED. My 800 PPFD space is consistent at 1.3-1.35 GPW over several strains and I suspect I can exceed that using lower light levels.

OTOH

Earlier this year there was a guy detailing his setup getting 1.5 GPW under 3 600s in a 4x8 using a flood table. Considering it was SOG the efficiency was doubly impressive at 56 watts per foot considering the g/ft was also noteworthy.

As far as 600s vs 1000s my understanding is that 1000s have slightly better efficiency, but if 600s are generally used in same spaces it does make sense that they would be hitting slightly higher GPW.

What makes sense to me is that for most hobby growers space is at a premium and it makes sense to max the light intensity. When I update my spaces I can see aiming for mid to upper 800s (PPFD), maybe in the 9s.
 

Bleedgreen

Active Member
Hey, I just wanted to say thanks for all of this. I have learned so much in a short amount of time and have cheated the curve by learning from your experiences...

I have just begun learning about this diy led stuff, and honestly about leds at all and already feel like i can at least come close to copying your design. the knowledge here is incredible.

I rarely post here but the diy stuff in this thread and others here are as inspirational to me as 3lb posts or when lucas was breakin down the numbers this isn't the future anymore it's the now...
 

pop22

Well-Known Member
I used GPW just because its the most commonly quoted stat. I myself am more interested in g/sq.ft and I would crank that 284 watter up and see what I got....... I'm not running a huge grow so all I care about is maximizing my yield and if I can do that using LED then that's how I'll do it. What it costs is not a big factor as long as it costs me less to grow than to buy!

HPS and all the accessory equipment it requires to keep it from frying your plants are all boat anchor candidates as far as I'm concerned. I gave away my 600 watt HPS, good riddance!

How much can I grow in x amount of space is my concern, as space is my limiting factor

No they wouldn't use G/W...A smart investor would use G/kWh. The other guy just went broke. G/kWh factors in time of use...which is what you pay for. As well as veg time and useage. G/w does none of that. It is a incorrect and misleading figure.

Exactly. Listen to what has been said for 40+years. 700-1000umols. This is no secret and plant don't give 2 shits where light came from and ,for all intents and purposes, what color it's in. Supply the quanta and get the results. G/kWh is how you supply quanta...not g/w.
 

Growmau5

Well-Known Member
I've got some initial numbers in from this 700ma harvest. I think its going to be hard for people to believe from a dry weight POV. Im documenting everything, and as boring as it is to watch a video where people weigh shit out, i think it will be necessary to prove my claims. I need a few more days to a week to make sure everything is completely dry and all of the nugs are at an acceptable hum%.

it will be somewhere between 1.8-2 gpw. granted 70% of it is white nightmare x blue dream, a high yielding somewhat decent quality strain.

stay tuned.
 

vahpor

Well-Known Member
I've got some initial numbers in from this 700ma harvest. I think its going to be hard for people to believe from a dry weight POV. Im documenting everything, and as boring as it is to watch a video where people weigh shit out, i think it will be necessary to prove my claims. I need a few more days to a week to make sure everything is completely dry and all of the nugs are at an acceptable hum%.

it will be somewhere between 1.8-2 gpw. granted 70% of it is white nightmare x blue dream, a high yielding somewhat decent quality strain.

stay tuned.
Maybe I missed it, whats the ~PPFD for the area you flowered in? Anymore larfy/leafy than higher intensities? Most BD crosses dense up pretty nice on their own. Just curious if you have run the same strain under the same/similar lighting at higher intensity.
 

Rahz

Well-Known Member
I've got some initial numbers in from this 700ma harvest. I think its going to be hard for people to believe from a dry weight POV. Im documenting everything, and as boring as it is to watch a video where people weigh shit out, i think it will be necessary to prove my claims. I need a few more days to a week to make sure everything is completely dry and all of the nugs are at an acceptable hum%.

it will be somewhere between 1.8-2 gpw. granted 70% of it is white nightmare x blue dream, a high yielding somewhat decent quality strain.

stay tuned.
Sounds great, looking forward to seeing those numbers! I think you're right as far as being among the first to hit those numbers... but I would be surprised if people don't start hitting 2+ GPW with 3590s. Can't remember who as it's been a few months but someone I thought trustworthy mentioned 1.8 GPW. More of that coming in from respected growers and video evidence will only be a good thing.
 

bassman999

Well-Known Member
Sounds great, looking forward to seeing those numbers! I think you're right as far as being among the first to hit those numbers... but I would be surprised if people don't start hitting 2+ GPW with 3590s. Can't remember who as it's been a few months but someone I thought trustworthy mentioned 1.8 GPW. More of that coming in from respected growers and video evidence will only be a good thing.
I would love to get 1g/W
 

BuddyColas

Well-Known Member
I've got some initial numbers in from this 700ma harvest. I think its going to be hard for people to believe from a dry weight POV. Im documenting everything, and as boring as it is to watch a video where people weigh shit out, i think it will be necessary to prove my claims. I need a few more days to a week to make sure everything is completely dry and all of the nugs are at an acceptable hum%.

it will be somewhere between 1.8-2 gpw. granted 70% of it is white nightmare x blue dream, a high yielding somewhat decent quality strain.

stay tuned.
That is impressive! You mentioned earlier that you ran your light bars with lens about 24” above the canopy. Without spending a huge amount of time can you give me a range in lux that your canopy was seeing about 24” below the lights? I too am running passive light bars at 700ma but with Vero 29s WITHOUT lens…so I am very interested in the lux levels you were seeing to get the kind of results you are getting. I may have to order some lens! Thanks.
 
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pop22

Well-Known Member
I for one, am looking forward to seeing your results!

I've got some initial numbers in from this 700ma harvest. I think its going to be hard for people to believe from a dry weight POV. Im documenting everything, and as boring as it is to watch a video where people weigh shit out, i think it will be necessary to prove my claims. I need a few more days to a week to make sure everything is completely dry and all of the nugs are at an acceptable hum%.

it will be somewhere between 1.8-2 gpw. granted 70% of it is white nightmare x blue dream, a high yielding somewhat decent quality strain.

stay tuned.
 
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