LED Lab 2009

[Weezard]

Me, that's who.

Me, that's who.

Who grows one plant under a 400? That's a pretty untypical grow.

How much are you yielding with 45W of LEDs?

Well, I'm a pretty un-typical guy.

Only had one plant at the time, brah
Mo' betta now.

Yield?
Have refer you to an earlier post.
I grow enough for myself.
I never run out.
I never sell my meds.
I don't do "pissing contests".
So, don't own, or need a scale.

With me, it's all about the stealthy, efficient production of something I need, but can not legally purchase or afford.

What is it with you?

Aloha,
Weezard

 

[Weezard]

I would love to get my hands on a Smartlamp or three.

I would love to get my hands on a Smartlamp or three.

To date the most well documented LED grows - though not plant specific - were at

http://www.greenpinelane.com/

He had the greatest success with the TI Smartlamp & TI Smartbar from Theoreme Innovation Inc.

http://www.theoremeinnovation.com

I'm curious to know what Knna or any other knowledgeable specialist think of this TI Smartlamp. The following is the marketing literature from the manufacturer.

The TI SmartLamp can be used as a supplemental lighting for greenhouse crops or as primary lighting in closed areas.

The light integrates the ballast, the reflector and the ventilation system required for its use. No assembly is needed. Its compact design minimizes shadow effects. The TI SmartLamp is suitable for power supplies in the range of 110V to 240V (50Hz/60Hz) and is equipped with a glass that provides a high light transmittance of up to 98.5%.


Area Coverage
Recommended lamp height above ground:

• Supplementary lighting: 1.8m (6 feet) or less*

• Primary lighting: 0.6m (2 feet) or less*

*Depending on the type of plant and the desired result.


Luminous Output
Total photosynthetic photon per unit of time
183 umol/s



Electrical Characteristics
Operating Voltage
110V - 240V

Operating Frequency
50Hz - 60Hz

Typical Power Consumption
300W***

*** 330W with the TI-ProBloom option



Other Characteristics
LED estimated life span
>50,000 hours

Light output maintenance after 50,000 hours
70%

Operating luminaire orientation
lighting downwards

Maximum surface temperature
65ºC (149ºF)

Operating temperature
(Indoor use only)
-20ºC to 40 ºC (-22ºF to 122ºF)

Run-up time (100% of final value)
less than 2 seconds

Knna mentioned that a balanced white spectrum would probably be more efficient in terms of efficacy. I'd be grateful if to know if the TI Smartwhite Industrial Series would be a better alternative in the veg stage than the marketed TI Smartlamp with its redder spectrum. Or would a person get more efficient or greater photon output from a similarly sized ceramic metal halide (250 -soon to be possibly released 300 - or 400 watt?

Many thanks to those who are able to offer any insight.

Alas, no can.
Anti-social in-security being what it is.
If I could afford 'em, I still could not afford to feed 'em.

Steve Fortier over at Greenpine was my original inspiration and guidance in light construction. I owe him for that.

Glad you happened along just now, I was getting discouraged.
'bout to go all "pearl nazi" on that last guy.
"No pearls for you"

There's so much information developed on cdot that starting over here is daunting. I, like Knna, was wondering if it's worth the effort.

So, we have 2 votes for a thread on building and perfecting Led lamps for Cannabis.
I'm underwhelmed.

later,
Weezard

 

[Bender]

K+ to knna and Weezard

This thread is off to a great start. After I've got enough grows under my belt that I feel confident with the plant I'd like to start experimenting with efficiency. I agree that people are failing the LED grows, not the technology. I have a friend who recently returned from Amsterdam and wants to start growing now. He doesn't know I grow so it was really hard to bite my tongue when he started telling me about how he was going to build a fully automated LED grow cab. I fear that he'll attempt to follow through with his plans and fail... ultimately leaving him discouraged and maybe not wanting to keep growing.

 

[Bender]

There's so much information developed on cdot that starting over here is daunting. I, like Knna, was wondering if it's worth the effort.

So, we have 2 votes for a thread on building and perfecting Led lamps for Cannabis.
I'm underwhelmed.

later,
Weezard

Vote #3 right here. Please guide us through the process of building the perfect CannaLED!

 

[knna]

Im glad to see serious interest on working together on developing the best LED growing lamp for MJ.

I would participate on a "Perfect LED grow lamp development", as far as people participating take in mind some things:

-Optimal light spectrum is specie dependent.

This an scientific fact. There is no magic spectrum able to work the best for any plant. Its possible to find an spectrum distribution that works fine for most species, but we should concentrate on finding the optimal spectrum distribution for cannabis. First, on one able to produce the larger amount of bud (per unit of light used). The final stage should be intended to find the best spectrum for resin production per unit light and explore the qualitative trade offs of different spectrums (is there a way to affect cannabinoids profile by light?).

There is little to no specific scientific info about MJ light response. We can research for general plant's response info, but from that, we will need to discover all about MJ and light for ourselves. And that requires testing and experimentation. A group of growers designing experimentation together and sharing results for sure is going to strongly reduce the time needed for this task.

We was researching on the net and botany literature the relevant info required for this experimentation. There has been several threads at this site and other ones since the OG times about this. Almost anything new since 2 years ago. We may resume it again for the new people incorporating to the research, but from now on, it must be mostly experimental.

-Is LED growing a current viable alternative or it is still on the experimental stage?

I think that until LEDs perfomance/cost has reached lately the level able to grow pot on enough amounts for own use, we still need to learn a lot about how to grow MJ using LEDs.

So a thread to develop the perfect LED grow lamp should consider LED growing like experimental. Priority should not be buds production, but experimenting on what works better and how spectrum affects MJ growth. Aditionally we need to explore if other environmental conditions (temperatures, humidity) should be adapted to LED growing, aswell as nute's profiles.

-Sharing results is only meangliful and useful if we use universally valid units, that can be extrapolated for one grow to another

We are not going to perform an scientific study. We dont need to do controlled experiments (although it would be great if somebody can perform it). But at least, we need to use meangliful units and standarized ways of measuring, so we can compare results. Without this condition, no any gain of knowledge is possible. Any research becomes individual and conclusions reduced to our setup conditions.

When we start experiments, we need accurate info about the conditions at they are performed. Concrete and accurate info.

We are used to some of them, on use currently, as temperatures, humidity, nutes (or better, elemental nute profile). Others are known but little used, because they are not relevant except when trying to make results meangliful, as standarized ways of weighting yield (wet yield, dry yield, dryness level, way of manicuring, etc).

But for lighting, we need to use units that had not been used before at the MJ forums. LED lighting caracteristics does older ways of explaining lighting setup absolutelly unmeanglifull:

Lm are absolutelly unuseful and very misleading when used with narrow bandwith light sources (monocolor LEDs).

Watts (burned watts) dont have any relationship with light emited either, because efficiency of LEDs have huge variations. It depends of the model, of the bin, and of the setup (current used, thermal resistance). 600w of any HPS emits a very similar amount of light. But 600w of LED may have so huge variations (perfectly of 3x more light emited on one setup than another) than using watts is still more unmeanglifull than lumens.

When working with LEDs, we need to use radiometric units: PAR watts or micromols of photons (abreviated, uE, microEinstein). PAR watts gives and accurate info about the light emitted, although it not take into account the spectral distribution. uE weight PAR watts according to spectrum, so its the best unit to use.

uE is a meangliful unit, that represents accuratelly the amount of light that plants uses. If we know how many uE are being used, we can calculate how efficiently the light is used. We can compare g/uE, for example, and its a comparable figure with other setup. It allows to use very different setups but keeping result comparable. Different LEDs, different current levels, different drivers.

Whats the problem with this? We need to know enough about LEDs used to know how many uE they emit. A grower that dont know how many uE is using can not help us on our research.

Peace,
knna

 

[GeneticHeirloom]

Vote #4 I love LEDS and would love to see this develop more and more.

(Also: You must spread some Reputation around before giving it to Weezard again)

 

[knna]

Who makes 640nm? I've only been able to find 620-630nm then 660s, also do you know of any place to buy the edison 660s and far reds (even though you don't recommend the 660s)

Beware of the small letter on LEDs specs. At the forums, we usually talk about radiometric peak wavelenght, that is what interest us. But manufacturers mostly gives dominant wavelengh (which correspond to how human perceives color).

625nm dominant wl red LEDs are usually about 632nm peak. And take in mind than that figure is given at Tj=25ºC (Tj=temperature on the junction's chip). LEDs vary spectrum as the chip heats. Red AlInGaP LEDs (most efficients currently) increase its peak wavelenght at about 0.14nm/ºC (if depends of the model, but it is give or take, aprox correct for most). It mean the a 625nm dominant wl LED have a peak wl on operating conditions (60<Tj>80ºC) between 635 and 640nm. Thus, 625nm dominant red LEDs are in fact 640nm LEDs.

Most manufacturers has the longer red bin of 625-630nm (dominant) aprox, which correspond, on operating conditions, to 635-645nm (up to 650nm if running hard).

Im going to get some Edixeon for testing this month. If i think they work fine, and there is demand, i could sell them (BTW, way cheaper than price quoted at LED tech, about 35% less). As i get large batchs of LEDs and components (drivers, heatsinks, etc) im thinking on selling kits for hobbyist wanting to do their own LED lamps. Im already doing it locally, it would be just shipping worldwide.

I want to perform some experiments with the far red edixeons (740nm) to determine its usefulness for growing and what amounts are required.

nlvigour, about the TI smartlamps. Those guys are one of the most serious and professional doing LEd growing lamps currently. And honest, being the only ones that gives the uE output of their lamps.

Said this, 183uE and less than 300uE for the pro version seems too litle. A 250 CMH is giving 250 uE at about 1/10 the cost (including reflector losses: bare bulb emits about 325 uE). Surely the TI is able of outperforming it by the spectral advantage, but not for a large difference.

IMHO, they have complicated too much the spectrum without weighting trade offs of incorporationg UV (UVA, by the way, not UVB, i believe) and other colors that currently has very low efficiencies (yellow, for example). For sure it seems to perform very well for the amount of uE emitted, meaning that the spectrum combination works well. But at the cost of a low overall efficiency (uE/burned watt) and high price.

I though it would be a very nice alternative if it cost about half. Aditionally, the normal TI has a low output, valid only for small spaces, and the Pro obligue to mess with water cooling. I dont understand why they dindt build it using more surface area, using just passive cooling and distruibuting way better the light

There are currently 400w CMH on sale. The Phillips Retro White emits 550uE.

About spectrum on veg/bloom. Just blue/red mixed are working pretty well on vegging cannabis. But on the bloom stage, more complete spectrums are outperforming clearly red/blue mixes. Not only more red, but some green, yelow and far red. A very easy way of achieving it is adding white leds to the red and blue mix, and increasing red percentage (reducing blues).

 

[nlvigour]

Thank You...

Thank You...

Thank you Knna for the prompt and detailed response. I'm pleased that Theomere Innovations have developed an effective light, but as previously addressed, prohibitively expensive for the PAR watts or micromols of photons (abreviated, uE, microEinstein) emitted as compared to a 250-400watt Philips HPS Retro White Ceramic Metal Halide.

Knna your contributions have always been valued by members. The IC community is very fortunate to have someone, such as yourself, who is knowledgeable and dedicated to pursuing serious inquiries into relative efficiencies of LED's.

I also applaud the suggestion of possibly building experimental LED kits for the community. In fact, most people here would rather purchase from you as you have demonstrated great passion, expertise, and technical know how as to gains in effiency can be squeezed out of LED's.

A special thanks to Weezard is also in order. It's nice to know that your interest, and hopefully documenation, will provide further case studies for others to benchmark against.

Wishing you all the best.

Kind Regards

 

[Weezard]

I'm just the electrician, or somebody like him.

I'm just the electrician, or somebody like him.

Vote #3 right here. Please guide us through the process of building the perfect CannaLED!

Mahalo nui, Bender

I'll be quite happy to share .
As long as you all are aware.
That I'm a cut and try kine guy.
Math and theory, jus' make me cry.

I'll give you all I know, fo' free.
Only guarantee? It work fo' me!
I can't say how, I can't say why.
I said befo', I cut, and try.

Wish I had mo' education, like Knna.
But I too ripped to study, mos' everyday.
So, you need numbers? Give me a pass.
Would not know a micro-einstein if it bit me on da ass.

(Sorry 'bout that. It happens.)

I homebrew all my beer and wine.
Grow all my fruits and vegetables on a 1/4 acre in paradise.
Got Tomatoes in DWC Aero, got potatoes in coco.
I try everyt'ng green on plants I'm not emotionally attached to before I risk $6 MJ seeds.
Tomato seeds are cheap, bro.!

Just checked out your bagseed site.
That's pretty darn nice, Bender.
You have a green thumb.

Hope you decide to experiment with LEDs
I agree that most led grow failures trace back to the grower.

I've never been very good at growing myself. Got a pitch black thumb.
So, I figure if I can do it, a geen thumber can do it mo' betta!

I do LEDs from necessity.
Sure the initial cost, of the light, even if DIY, is a li'l high.
But, usually, so am I.

Got a little cancer problem, but it's slow growing, so I plan for about 8 to 10 years. When I factor in longevity of the emitters and the outrageous cost of power here, the choice is clear.
I'm concerned with on-going expenses and figure the LEDs will amortize mo' betta than HPS, or even CFLs in the long run.
That said, I am surprised and extremely pleased by my little garden.
It serves.
Guess I'd better start a thread and quit this one.
Might take a while to think up a good title.
Any suggestions?

Aloha,
Rambling Weezard

 

[Thundurkel]

Great job guys! this thread is awesome I've been saying the CFL's and LED's are the wave of the future for indoor growing especially for micro grows or anything 400w or smaller. Keep up the good work I would love to see more pics

 

[indifferent]

I'm putting the finishing touches to me new LED light then I'll borrow a cam and take some pics. I've got three 700mA 68V drivers (50W each), each running 14 red CREE XR-C stars, 4 CREE XR-E cool white P4s (not the latest most efficient bin but I got em cheap), 2 red Luxeon K2 warm white stars and 5 Prolight UV stars. The middle bank of the three has 5 CREE XR-E R2s instead of the Prolight UVs.

I have in total:

42 x CREE XR-C red
12 x CREE XR-E p4 cool white
6x Luxeon K2 warm white
5 x CREE XR-E R2 cool white
10 x Prolight UV

That's a total of 75 LEDs mounted to an array 240mm x 240mm made by joining together 9 Akasa AK-860 Pentium4 heatsinks. I'll be using this LED array in a 600mm x 600mm tent. I'm hoping this will be sufficient photonic energy to produce a meaningful result. My previous LED experiment used 3w Luweons running at 1400mA and LEDengin 660nm 5W runnign at 1000mA. I think the LEDengins are crap, the max vf of tthe 5 I have on my old array is 2.5V so they are only 2.5W devices, not the 5W claimed, and the stars they are mounted on are crap, very very difficult to get a good solder joint on them, never had this problem with any other star LEDs. I decided not to bother with edison or LEDengin 660nm LEDs for my new array as, like knna mentioned, they are expensive and low output compared to other red available.

I agree that the TI smartlamp and smartbar are by far the best products on the market currently, I attribute this to the wide range of LED types they have used. Quite clearly, just blue and red doesn't work, which is why I am using white LEDs instead of blues. I've looked at TI's literature and I can't find any info on what LEDs they are using, I think they are using a mix of Luxeons, Seouls and Edisons, judging by the pictures someone took of their unit.

There is a Dutch company called flowmagic that have been around a while, they have a good looking light that uses edison opto LEDs, they use a number of types and give full details on their website, the drawback is the 38W small test unit is 500 euros, I forget how much they were charging for the large water cooled units.

The list of LED types used by flowmagic:

The Agro LED System spectra:

Daylight (extra)
Soft White
Warm White

Uv 400 Nm
Blue 450 Nm
Red 640 Nm
Red 660 Nm
Farred 740 Nm

I have the cool white, warm white and 640nm in my LED array, the aim being to have a full spectrum output with a heavy weighting towards the red end of the spectrum.

My warm whites actually put out some output in the far red range, which means I don't need to buy 740nm LEDs for my array, but I'm interested in try phytochrome forcing so I may end buying some 740nm LEDs and making a smaller array to switch on at the end of the lights on period to force phytochrome-fr reversion.

My other thought on correct spectra for flowering cannabis is amber light. HPSes put out a hell of a lot of amber/orange light and I reckon the cannabis plant must convert it internally so it can use it like it uses red light. I'm wondering if adding a number of amber LEDs to an LED light would be a worthwhile experiment.

One topic I haven't seen mentioned here yet is experimenting with light regimes other than 12/12. A guy came in the cannabis.com LED thread with wild claims of having developed a 'Martian Method' where they ran the light above 600nm 24/7 and only turned the sub 600nm light on and off each day to simulate daytime. I am highly dubious about the guy's claims, he seemed very evasive when giving specifics. Some people in that thread began experimenting with incandescent light bulbs that had red glass (not painted red) that only output red, far red and infrared as well as mixing CFLs and CCFLs with the LEDs. I think one of the biggest advantages of using LEDs for growing, and one that most folks seem to have not addressed, is the way LEDs allow you to change the spectrum of light delivered to the plant throughout the 24 hour cycle. I think it may be a better solution to try and mimic more closely the way nature works and instead of using the traditional on/off 12/12 method of flowering, to vary the light spectrum and intensity during the cycle. I think it may be better to have more red at the beginning and end of the day to simulate sunrise and sunset, and to add UV during the middle of the day cycle to simulate the higher UV levels at noon as the sun is overhead.

I also think there is experimentation to be done with changing the spectrum of light for different flowering phases, with more blue light in the first half of flowering to promote vegetative growth and more red light with less blue in the second half of flowering to promote greater flower production, this would simulate the changing spectrum of light in autumn.

One thing I have discovered so far in my LED experiments, the LED buds had increased smell and taste, even a tiny plant yielded a few grams caused odour worries! I think this is due to the greater amount of blue light stimulating production fo greater amounts of carotenoid terpenoids. This is something else I think worth experimenting with. Folks say CMH produces better buds than HPS, and that may be because of the greater blue output of a CMH. The way to test this would be to do two flower runs of the same clone, one with a load of blue LED light and one without, then compare the smell and taste of the end product.

 

[ballast]

greetings all so sorry computer problem catching up now and plenty to say soon, weezard knna indifferent all you guys thank you for dropping in, dont care who's thread it is just glad to have gotten the train out the station still holding off ordering anything yet with so much uncertainty, tho pretty much set on ledengin 660's unless solmething else turns out better

 

[knna]

Hey, Weezard, i would like to point out that im not critiziting LEDs setups that dont know their uE emission and spectra distribution. If they works and produce what you need, its great. I have no any problem with this, for your setup or anybody else one.

I just say that it isnt valid to increase our knowledge of how different spectra works, as we need to have quantitative references.

If i wrote my last post is because i feel most people want to follow your way. There is nothing wrong on it, but i think is impossible to improve and develop better LED systems without answering "how much" and "how many" questions. My post is intended to stand the conditions for a group research and improvement LED grow thread, and its not related to those who just want to grow some pot with LEDs.

indifferent, i like very much the array you are building. If you tell me what bins are the Red XR-C and the K2 WW, i could be more accurate. But roughly, it is going to emit about 150uE (on PAR, UV excluded), meaning an average light density of more than 400 uE/m2, that promises a good yield. RGB (B=400-500nm, G=500-600, R=600-700nm, simplified ranges) distribution about 65-20-15% which i believe is a very good one.

With the amount of far red added by the whites (specially the WW), i believe you are done. Although at some special stages, mainly flowering induction, an higher amount of far red should shorten the time needed to reach true flowering (but its as simple as adding an incandescent bulb during the first week after flipping photoperiod at the end of the light period, for 1/2h). I think that having an far red LED's spot for this purpose, aswell as controling phenotype expression would be very useful, but not strictly required.

I believe terpene's production enhancement is related to short blue, violet and UVA, although i think its effects are modulated by the amount of other colors (i suspect yellow and amber).

You dont say how are you going to grow with that array. Scrog, sog, LST? with all the light on top of plants, they cant be tall. If you want to grow taller plants, i think you should consider mounting each heatsink separatelly, in order to being able to put some of them on the sides at lower height and give side light, instead of giving all the light from top. With a modular design (each heatsink being a module) you can try different configurations and check what works better.

 

[indifferent]

Hi knna

I'm afraid I don't know the precise bin codes for the K2s, I got there here for only $3.10 each, I felt for the price (cheapest 3W star around) and the very nice spectrum for growing, they were the best choice. I would have preferred the new TFFC version but those are much more expensive at the moment.

http://kaidomain.com/ProductDetails.aspx?ProductId=1632

I suspect the K2s I have are 100 lumen LXK2-PW14, but I may be wrong.

The CREEs I have I know more details about.

These are the coolwhite XR-E P4s I have - XR7090WT-U1-WD-P4-0-0001, at 17 dollars for 5, I have to grab them, even though a Q5 or R2 bin gives more lumens, they are $6.50 each, so again I took the cheaper option:

http://www.dealextreme.com/details.dx/sku.2134

Here are the R2s I bought - XREWHT-L1-WG-R2-0-04:

http://www.dealextreme.com/details.dx/sku.15943

The red CREE XRs are here - there is no info on bin code, sadly:

http://www.dealextreme.com/details.dx/sku.1776

Actually, four of my reds are nto CREE XRs, they are made by CML but they should be identical to the XRs in performance as they use the same CREE chip, when you looks at them closely, you can see they are internally identical, just the packaging differs. I got these four really cheap when Farnell had a clearance sale, I've been collecting parts for a couple of months and picking up things when I see them at a cheap price.

I put a lot of thought and research into designing my array, so I'm delighted your opinion on the RGB ratios I have concurs with what I was able to figure out, my knowledge is on a less scientific basis than yours, I consider you to be the moist knowledgable person on any forum regarding the topic of LEDs and there use for photosynthesis so is you say I have the right ratios, that's good enough for me!

I bought a pair of Osram 28W Halogen bulbs (they look like a normal incandescent bulb but with a halogen capsule inside rather than a filament) and used them to supplement my old 80W Luxeon array (along with 2 x 20W warm white CFL) and I don't know if they made much difference, nut I can always try again in the way you suggest to stimulate phytochrome-fr reversion and hopefully induce flowering more rapidly.

I don't know what effect the UV in my array will have (well, it's near UVA. not true UV) but I didn't have any UV in my Luxeon array, just reds and warm whites and I decided to include some in my new array to see if I can notice any difference with UV.

Grow style will be either 4 or 6 clones, I will keep them no more than 9 inches tall with pruning and supercropping, I will grow them with flat canopies. Wish my HD hadn't died 2 weeks ago as I have pics of my last LED plants and those were grow in this way, flat canopy with lots of budsites, almost like a SCROG but without the net. I will chose a pure indica, a pure sativa and a couple of hybrids, I feel this will give a better basis for testing than using just one variety.

Could you tell me how many uE/m2 a 250W HPS (Osram SON-T) would produce in a 600mmx600mm space with the lamp placed 80cm above the centre? I'm interested in this figure as I want to use a 250W HPS as a baseline for comparison. I will grow the same clones under the LEDs then under a 250W HPS in order to get a fair comparison. I tend to average somewhere between 0.8 and 0.9g per watt with a 250 with 6-8 plants in 4 sq ft so that is my goal - to match the results of a 250W HPS using LEDs.

 

[TheShroomDude]

Im glad to see serious interest on working together on developing the best LED growing lamp for MJ.

I would participate on a "Perfect LED grow lamp development", as far as people participating take in mind some things:

-Optimal light spectrum is specie dependent.

This an scientific fact. There is no magic spectrum able to work the best for any plant. Its possible to find an spectrum distribution that works fine for most species, but we should concentrate on finding the optimal spectrum distribution for cannabis. First, on one able to produce the larger amount of bud (per unit of light used). The final stage should be intended to find the best spectrum for resin production per unit light and explore the qualitative trade offs of different spectrums (is there a way to affect cannabinoids profile by light?).

There is little to no specific scientific info about MJ light response. We can research for general plant's response info, but from that, we will need to discover all about MJ and light for ourselves. And that requires testing and experimentation. A group of growers designing experimentation together and sharing results for sure is going to strongly reduce the time needed for this task.

We was researching on the net and botany literature the relevant info required for this experimentation. There has been several threads at this site and other ones since the OG times about this. Almost anything new since 2 years ago. We may resume it again for the new people incorporating to the research, but from now on, it must be mostly experimental.

-Is LED growing a current viable alternative or it is still on the experimental stage?

I think that until LEDs perfomance/cost has reached lately the level able to grow pot on enough amounts for own use, we still need to learn a lot about how to grow MJ using LEDs.

So a thread to develop the perfect LED grow lamp should consider LED growing like experimental. Priority should not be buds production, but experimenting on what works better and how spectrum affects MJ growth. Aditionally we need to explore if other environmental conditions (temperatures, humidity) should be adapted to LED growing, aswell as nute's profiles.

-Sharing results is only meangliful and useful if we use universally valid units, that can be extrapolated for one grow to another

We are not going to perform an scientific study. We dont need to do controlled experiments (although it would be great if somebody can perform it). But at least, we need to use meangliful units and standarized ways of measuring, so we can compare results. Without this condition, no any gain of knowledge is possible. Any research becomes individual and conclusions reduced to our setup conditions.

When we start experiments, we need accurate info about the conditions at they are performed. Concrete and accurate info.

We are used to some of them, on use currently, as temperatures, humidity, nutes (or better, elemental nute profile). Others are known but little used, because they are not relevant except when trying to make results meangliful, as standarized ways of weighting yield (wet yield, dry yield, dryness level, way of manicuring, etc).

But for lighting, we need to use units that had not been used before at the MJ forums. LED lighting caracteristics does older ways of explaining lighting setup absolutelly unmeanglifull:

Lm are absolutelly unuseful and very misleading when used with narrow bandwith light sources (monocolor LEDs).

Watts (burned watts) dont have any relationship with light emited either, because efficiency of LEDs have huge variations. It depends of the model, of the bin, and of the setup (current used, thermal resistance). 600w of any HPS emits a very similar amount of light. But 600w of LED may have so huge variations (perfectly of 3x more light emited on one setup than another) than using watts is still more unmeanglifull than lumens.

When working with LEDs, we need to use radiometric units: PAR watts or micromols of photons (abreviated, uE, microEinstein). PAR watts gives and accurate info about the light emitted, although it not take into account the spectral distribution. uE weight PAR watts according to spectrum, so its the best unit to use.

uE is a meangliful unit, that represents accuratelly the amount of light that plants uses. If we know how many uE are being used, we can calculate how efficiently the light is used. We can compare g/uE, for example, and its a comparable figure with other setup. It allows to use very different setups but keeping result comparable. Different LEDs, different current levels, different drivers.

Whats the problem with this? We need to know enough about LEDs used to know how many uE they emit. A grower that dont know how many uE is using can not help us on our research.

Peace,
knna

^^^^What he said!!!^^^^^

 

[indifferent]

^^^^What he said!!!^^^^^

Lol I agree bro!

The bit about needing to be precise and take measurements is worth emphasizing. No offence to weezard, but without details and measurements, it's impossible to gain much insight at all into his results. However, what weez brings to the table is practical experience with the hardware.

 

[Weezard]

Follow my way?! No follow me, I wander.

Follow my way?! No follow me, I wander.

Hey, Weezard, i would like to point out that im not critiziting LEDs setups that dont know their uE emission and spectra distribution. If they works and produce what you need, its great. I have no any problem with this, for your setup or anybody else one.

I just say that it isnt valid to increase our knowledge of how different spectra works, as we need to have quantitative references.

Exactly what I depend on you lot for.
I just get lost in all that detail.

Quit even trying to measure lux n lumens n all when I realized the major advantage of leds.

Inverse square law to the rescue.

Ignoring all other factors.
Do I burn a kilowatt and keep it 18" from my ladies.
Or 250W. at 9" or 60W at 4.5" .

Screw it!
45W., (Not of light emission mind you, just of total power consumed ), 2 inches from the canopy serves me just as well.
Any closer and I get "bleaching" from too much light.

If i wrote my last post is because i feel most people want to follow your way. There is nothing wrong on it, but i think is impossible to improve and develop better LED systems without answering "how much" and "how many" questions.

There's that word again! I disagree.
Difficult, yes. But, Impossible?
Dis li'l pig stumbles blindly along and find acorns everywhere!
Would it be easier with an intimate knowlege of Oak tree physiology? Absolutely!
But, again, that's what I depend on my educated brothers for.

I'm a practical type.
My first attempt at leds was dissapointing.
So, I started some clones in dwc. Put 2 under leds and 2 in full tropical sun. When all 4 ended up spindly I figured it was not the light, it was the grower.

Hit the books until I had the other factors "dialed in" and then got the results I wanted without supporting HELCO. (Hawaiian Electric)

So, please do keep "jerkin' it to the numbers."
Eventually, someone will "dumb it down" enough for me to understand.


I'd love to have someone say;


Use 8 of these, n 12 of those,
Cross yer fingers an' yer toes
Addem to da red an' blue,
Makes yer buds swell-up times 2!


Then If their picture match their theory,
I'm in and I'm grateful.


My post is intended to stand the conditions for a group research and improvement LED grow thread, and its not related to those who just want to grow some pot with LEDs.

Understood!
That's why I intend to start a thread for "the rest of us".

I read here that it's impossible to grow good buds with just red and blue.

I no argue, I jus' blaze a bowl of my fat, dank, impossibilities and let my grin spread till it hits my ears.

.

Mahalo for sharing.
Will try to return the favor, best I can.
"I will gladly pay you Wednesday for a great idea today"

Aloha,
Weezard

 

[knna]

(sorry, double post) (BTW, no more delete post option: i dont like to help increase profits of people who dont care of their "clients")

 

[knna]

Thanks for the compliments, i really appreciate it. I had a bad time in this board that led me to delete my posts. Some trolling and very bad moderation. But i received many personal messages encouraging me to continue posting, and knowing my posts are useful for other people is my fuel to continue doing it.

indifferent, at those prices on those shops, probably both the K2 WW and the XR-C red are low bins. On the WW it dont do much difference, but it does on the reds. They are probably K bins, and i feel the M bin is required to be able to compete with HPSs. My estimations were using the bin M. If they are K bins, then the uE are going to be 120 as max. On 0.36m2, it means an average light density of 330 uE/m2. Probably insufficient to get huge colas as grown under HPSs, but enough to get a decent harvest.

The Osram NAV-T 250w gives about 315uE, about 235uE avalaibe for plants after reflector losses. You are going to get about half uE using about half watts (a little more with the UV). With the K bin, radiant efficiency (uE/burned watt) of the LED setup is going to be slighty lower. I think you should compensate it with better efficacy of the spectrum (g/uE). Getting from your array an harvest about half of that of the 250w should be the minimun to expect. Getting same yield than the HPS using half photons is going to be difficult, IMHO. Surely you can get an higher quantum productivity (g/uE), as about 25% over the HPS. But getting the harvest of the HPS should need to double the spectrum efficacy that would require an almost perfect spectrum (i doubt if it is possible to double the quantum efficiency of the already good HPS spectra, at least for cannabis).

Anyway, we dont know what spectral efficacy it is going to have until testing it. Maybe it works awesome and its is able to compete with the HPS. Im looking forward for your results.

IMO, using top bin is a must currently to be able to compete with HPSs watt per watt, and get electric savings that compensate the initial higher cost of a LED setup. Especially for the red leds. If your reds are M bins, what emits near 1/3 more photons per watt burned than a K bin, then the task for sure would be easier.

 

[indifferent]

Thanks for the compliments, i really appreciate it. I had a bad time in this board that led me to delete my posts. Some trolling and very bad moderation. But i received many personal messages encouraging me to continue posting, and knowing my posts are useful for other people is my fuel to continue doing it.

That mirrors my experience here earlier, and also at some other places when discussing LEDs. I spent a lot of time and effort carefully documenting all my LED experiments and as a result i had to deal with endless trolls saying 'LED's are shit' and even worse from a tiresome point of view, so many people PMing me with questions, they didn't wanna do any hard work themselves in terms of research or experimentation, they just wanted someone to tell them what they needed to know. Besides yourself and one or two other folks, no-one had anything useful to contribute, advice to give, etc, it got really tiresome so I just stopped posting about my LED work and carried on.

indifferent, at those prices on those shops, probably both the K2 WW and the XR-C red are low bins. On the WW it dont do much difference, but it does on the reds. They are probably K bins, and i feel the M bin is required to be able to compete with HPSs. My estimations were using the bin M. If they are K bins, then the uE are going to be 120 as max. On 0.36m2, it means an average light density of 330 uE/m2. Probably insufficient to get huge colas as grown under HPSs, but enough to get a decent harvest.

I agree, I went for the cheapest option as I'm on a very tight budget, I expect the best red CREE bins go straight to companies like the people who make the Procyon and it is the lowest bins that are disposed of cheaply through the far east market. My preference would be to use Luxeon Rebels for my reds as the bare emitters are very cheap, but trying to mount and solder those tiny little things would drive me mad! To buy the better binned CREEs would have more than doubled the cost so it's a compromise between price and performance, always annoying when economics get in the way of hard science! lol

The Osram NAV-T 250w gives about 315uE, about 235uE avalaibe for plants after reflector losses. You are going to get about half uE using about half watts (a little more with the UV). With the K bin, radiant efficiency (uE/burned watt) of the LED setup is going to be slighty lower. I think you should compensate it with better efficacy of the spectrum (g/uE). Getting from your array an harvest about half of that of the 250w should be the minimun to expect. Getting same yield than the HPS using half photons is going to be difficult, IMHO. Surely you can get an higher quantum productivity (g/uE), as about 25% over the HPS. But getting the harvest of the HPS should need to double the spectrum efficacy that would require an almost perfect spectrum (i doubt if it is possible to double the quantum efficiency of the already good HPS spectra, at least for cannabis).

Thankyou for that information, this paragraph does a better job of explaining the science behind the issue of LED vs HPS performance than anything else I have read so far!

I agree with you that it is doubtful an improvement in spectral efficiency of 100% is unlikely, largely because our knowledge of the precise photosynthetic requirements of a flowering cannabis plant is so incomplete - NASA experiments growing potatoes and salad greens under red and blue LEDs are not going to produce any useful data for the cannabis grower beyond proving that LEDs can power the photosynthetic processes of a plant. When we have finally learnt the precise spectral requirements of flowering cannabis we will be able to accurately design our LED lighting systems, but in the meantime, its all informed guesswork and to be honest, if someone does find the correct spectrum it will be more by luck than anything else at this point.

The other factor is the differences in technique that LEDs make possible - manipulation of spectrum during flowering, phytochrome forcing etc. It is probably the case that LEDs will not give their best results when used in the traditional 12/12 method and we will have to develop a whole new method in order to leverage the full potential out of out LED lights. Perhaps using my array in the 12/12 method I can get 50% of the performance of a 250W HPS, but with experimentation and a different light regime I could make a decent improvement on that performance.

Anyway, we dont know what spectral efficacy it is going to have until testing it. Maybe it works awesome and its is able to compete with the HPS. Im looking forward for your results.

Thankyou, fingers crossed the LEDs I bought are upto the job.

IMO, using top bin is a must currently to be able to compete with HPSs watt per watt, and get electric savings that compensate the initial higher cost of a LED setup. Especially for the red leds. If your reds are M bins, what emits near 1/3 more photons per watt burned than a K bin, then the task for sure would be easier.

Yes, I agree. I wasn't aware of the issue with the red CREEs although I should have realised as I'm well aware of the binning process and the whole range of different CREE XR-E white bins there are with different lumen outputs.

Just out of interest, what currently available LEDs do you think offer the best performance potential for the cannabis grower?