Discussion of the pragmatic application of LED's

[knna]

VG is not the only to have reversed the "natural" airflow, I know others who did and its working perfect. I think we may consider this as a default for LED grows where high temperature is not a problem. That way we send the heated and CO2 rich air directly to plants.

OneQ, beam angle to use is one of the topics where there is different opinions. Very often opinions about it are based on wrong info, but the fact is that is very difficult to say theoretically which is better. Its a clear case where we need the pragmatic approach.

In order to compare, its very difficult to compare results due different beam angles usually are acompanied by many other different things, and its hard to tell what is result of what. Usually when we change LEDs of a given beam angle for others, we change of model and bin, so not only beam angle changes, but light emission and spectrum yet. So the only way to extract some conclusion is by the brute force of many different grows using different beam angles. Kind of qualitative analysis that may be very subjetive.

All I can say about this is I use very wide beam angles LEDs and they work perfect. But I would love to have same LEDs Im using right know offering about 90º beam angles or still a little narrower yet. At least for the top lamps, I believe the widest beam angles are by far better on side/intracanopy lighting.

 

[one Q]

Yes, I can see how that will take a few years to get enough info to make a firm fact out of it.

So then I ask about the WATTs of the diode. In your exp is it better to use fewer "larger" watt diodes or more smaller watt diodes even if they equal the same TOTAL watts?

I ask this because I see Company A uses lots of 1w, Company B uses fewer 3w, and Company C uses even fewer 5w diodes. They are all in the similar price and total watt range so I look at them and wonder which would be "better?" Assuming theyre all using quality parts and what not. Assuming that all three would cover the given space well. Should I just be trying to get THE MOST WATTS in a given space? That makes the choice easy. Should I be trying to get the HIGHST powered LEDs...?

Thanks for the advice...
Q

 

[knna]

Yes, I can see how that will take a few years to get enough info to make a firm fact out of it.

So then I ask about the WATTs of the diode. In your exp is it better to use fewer "larger" watt diodes or more smaller watt diodes even if they equal the same TOTAL watts?

I ask this because I see Company A uses lots of 1w, Company B uses fewer 3w, and Company C uses even fewer 5w diodes. They are all in the similar price and total watt range so I look at them and wonder which would be "better?" Assuming theyre all using quality parts and what not. Assuming that all three would cover the given space well. Should I just be trying to get THE MOST WATTS in a given space? That makes the choice easy. Should I be trying to get the HIGHST powered LEDs...?

Thanks for the advice...
Q

I have used both ("1W" and "3W"). Really, I dint noticed differences due it, as far as total light delivered is similar.

Other thing is you can get more light using "1W" LEDs than using "3W" LEDs burning same watts, due LEDs are more efficients as you run it softer. Softer mean lower current density at the chip. "1W" category stand for LEDs running at 350mA and "3W" category stands for LEDs running at 700mA. But chips used for both categories are very similar is size (indeed, sometimes is the same), generally "3W" LEDs uses 1 sq mm chips and "1W" uses 0.75-1mm side chips (0.9mm is the most usual). Thus the current density is usually near double for 3W LEDs and that mean lower efficiency for a chip of same quality.

So I would say that all depends of which bin is the 1W and the 3W LED being compared (or the 5W ones). If each manufacturer of each lamp using one of the other says you which bin they are actually using, it would be way easier to tell what will work better.

But wait other people chime it and comment their experiences using both types, sure some disagree.

 

[VerdantGreen]

having used 60degree and 90degree my early conclusions are that 90degree seem to work better for my technique (scrog in very limited height). i can get the canopy a bit closer and the light shining down at a wider angle seems to get into the canopy better even though the 60degree will have more penetration straight downwards.

 

[Weezard]

Bump time. HG has been offline, longtime.

Bump time. HG has been offline, longtime.

This thread deserves a Bump.
A discussion of light concentration would be productive.

Hope you're feelin' betta, HG.

Aloha,
Weeze

 

[Snuff]

Very interesting thread and I want to share my experience with LED light.

I use 300W LED light (actual consumption 230W) in a small grow box 127H*56W*35D cm (near 2 sq. ft). A link to my current grow journal is in my signature.

The lamp was 6-10" above the top of the canopy during vegging and the beginning of flowering.
After a while I noticed that the plant was very bushy and unusually compact.

Day: 25, 18/6: 20


I thought that this is possible because a 230W LED light is overkill for my small box.
I began to search the literature on the influence of light on growing plants.
My search showed that I was right and the lamp gave an illumination level that the plant was a dwarf.

Here are some pics from the scientific article I read:



It is showed what makes with plants excessive light (over saturation point).

Also researches conclude that the ratio of spectral energy in the grow lamps is desirable to have the following (PAR): 25-30% in the blue region (380-490 nm), 20% in the green (490-590 nm) and 50% - in the red (600-700 nm).

Here is a couple of very interesting articles in Russian (google translate) on the effect of light on plant growth.

Growing plants under artificial light as a way to identify potential plant productivity.
http://translate.google.com/translate?hl=ru&sl=ru&tl=en&u=http://perchina.narod.ru/boev3.htm

Growing plants under artificial light in greenhouses.
http://translate.google.com/translate?hl=ru&sl=ru&tl=en&u=http://www.greenhouses.ru/Svetokultura


And here is a list of the scientific articles on cannabis sativa growing
http://home.olemiss.edu/~suman/

Ome of the most interesting articles from the previous link:
Photosynthetic Response of Cannabis sativa L. to Variations in photosynthetic photon flux densities, temperature and CO2 conditions.
http://www.olemiss.edu/~suman/PhysiologyandMol.Biol.2008.pdf

 

[Weezard]

Welcome!

Welcome!

Very interesting thread and I want to share my experience with LED light.

I use 300W LED light (actual consumption 230W) in a small grow box 127H*56W*35D cm (near 2 sq. ft). A link to my current grow journal is in my signature.

The lamp was 6-10" above the top of the canopy during vegging and the beginning of flowering.
After a while I noticed that the plant was very bushy and unusually compact.

Day: 25, 18/6: 20


I thought that this is possible because a 230W LED light is overkill for my small box.
I began to search the literature on the influence of light on growing plants.
My search showed that I was right and the lamp gave an illumination level that the plant was a dwarf.

Here are some pics from the scientific article I read:

Most of us learned that the hard way.
Even a crappy 90W Ufo will stop growth if it's too close to the crown.
Too high a B:R ratio will keep them squat as well.
I have variable ratio lights and can "tailor" the plants size a bit, by changing the ratio, depending on the strain of course.



It is showed what makes with plants excessive light (over saturation point).


However, that's not always a bad thing.
You'll note that the stunted Sunflower has as much, or more, seed than the one that "stretched to the light".
Easier to harvest, less waste, That's why we scrog, yah?

Also researches conclude that the ratio of spectral energy in the grow lamps is desirable to have the following (PAR): 25-30% in the blue region (380-490 nm), 20% in the green (490-590 nm) and 50% - in the red (600-700 nm).

I disagree, Practice seems to show otherwise.

Here is a couple of very interesting articles in Russian (google translate) on the effect of light on plant growth.

Growing plants under artificial light as a way to identify potential plant productivity.
http://translate.google.com/translate?hl=ru&sl=ru&tl=en&u=http://perchina.narod.ru/boev3.htm

Growing plants under artificial light in greenhouses.
http://translate.google.com/translate?hl=ru&sl=ru&tl=en&u=http://www.greenhouses.ru/Svetokultura


And here is a list of the scientific articles on cannabis sativa growing
http://home.olemiss.edu/~suman/

Ome of the most interesting articles from the previous link:
Photosynthetic Response of Cannabis sativa L. to Variations in photosynthetic photon flux densities, temperature and CO2 conditions.
http://www.olemiss.edu/~suman/PhysiologyandMol.Biol.2008.pdf

A pleasure to meet you sir.
Great links, Thank you!
I'll be a while digesting them. <urp>

Aloha,
Weezard

 

[blimblom]

I would like to bring us back to the ventilation question. As LEDs dont produce so much heat, KNNA, VG and others have suggested that we reverse the usual flow (bottom intake, top exhaust).

In that way, according to them, hot air will come through the plants and out at the bottom, helping them maintain the 25-28 C our plants need to thrive

Im constructing my cab pretty much similar to snuff's (35x60x140) and I am now in the part of choosing the air flow. As I am targeting a low noise cab (the small closet will be in my bedroom), I will be using a 12cm PC fan as an exhaust fan blowing to a carbon sheet and out of the closet.
The carbon sheet will make the flow even more difficult. I will also use passive intake through light traps on the top of the cabinet.
The cabinet wont be airproof, but I believe that I'll have no smell issues due to the negative pressure inside the cabinet.

I have the following concerns.
As I will be using LEDs, heat wont be an issue. Im planning on nearly 70-80Watt.
But the natural flow of the heat will be from bottom to top so Im afraid that heat will build up to the top .
I could put another fan inside the cab, pushing the air down, but Im trying to make it as noiseless, as I can.

so how many degrees over ambient temperatures your cabinet is, and what kind of airflow to you use??

 

[BloodyBeer]

Hi guys!!

I need advice - I´m thinking to buy one of this LED lights

http://www.quantumled.co.uk/servlet/...hip/Categories

the details are aprox follows:
1. What is the angle of the light - 120,90 or 60°??
2. How many of the 660nm leds are actualy on board??
3. And the last question ;-) is How many lumens does it have (compare to normal 90W UFOs)?

1.we mix 90 and 120 angle, we find this to be best.
2.40% 660nm 30% 630nm and 30% 460nm blue.
3.and its about 40% brighter then ufo 90w.

with price 180 quid

or

http://www.led-grow-light-sales.co.u...led-grow-light

here you can have 660nm red light colour and you can add UV light as well .... for 160 quid

my growing box is 50x50 cm so I think It will fits

So what do you think?? For me the UFO is winning (compare power to price) a little bit but I need another opinion ;-)

thanx

 

[Weezard]

Caveat emptor!

Caveat emptor!

Hi guys!!

I need advice - I´m thinking to buy one of this LED lights

http://www.quantumled.co.uk/servlet/...hip/Categories

the details are aprox follows:
1. What is the angle of the light - 120,90 or 60°??
2. How many of the 660nm leds are actualy on board??
3. And the last question ;-) is How many lumens does it have (compare to normal 90W UFOs)?

1.we mix 90 and 120 angle, we find this to be best.
2.40% 660nm 30% 630nm and 30% 460nm blue.
3.and its about 40% brighter then ufo 90w.

with price 180 quid

or

http://www.led-grow-light-sales.co.u...led-grow-light

here you can have 660nm red light colour and you can add UV light as well .... for 160 quid

my growing box is 50x50 cm so I think It will fits

So what do you think?? For me the UFO is winning (compare power to price) a little bit but I need another opinion ;-)

thanx

Guess I should start with the bad news.
(Since there isn't any good news here.)

On the second vendor, I found this;

"A 90W LED grow light replaces HID/Sodium 400W to 600W"

That, sir, is horse exhaust!
Run from them!
(A good 90W UFO will replace a 200W. HPS).

And reading the "bash" page from the first vendor sure smelled a lot like Cammie McKenzie.
(A notorious thief from the U.S.)

They labeled 10mm. leds as 3W.?!
"There ain't no such animal."

If that company is not at least a year old, run from them!
They both look very dodgy indeed.


I'm sorry that I can't recommend a vendor for ya.
But, I roll my own lamps and do not sell them.


No worry, I have no doubt that there will be several led-heads that do use commercial lamps showin' up soon.


Aloha,
Weezard

 

[unclefishstick]

my much maligned hydrogrow LED has been working just fine for me so far,dont have any complaints yet,will have a completed bud run in a few weeks to know for sure...

hey weezard,hope HG is doin ok,been a while since he was around...

 

[BloodyBeer]

Guess I should start with the bad news.
(Since there isn't any good news here.)

On the second vendor, I found this;

"A 90W LED grow light replaces HID/Sodium 400W to 600W"

That, sir, is horse exhaust!
Run from them!
(A good 90W UFO will replace a 200W. HPS).

And reading the "bash" page from the first vendor sure smelled a lot like Cammie McKenzie.
(A notorious thief from the U.S.)

They labeled 10mm. leds as 3W.?!
"There ain't no such animal."

If that company is not at least a year old, run from them!
They both look very dodgy indeed.


I'm sorry that I can't recommend a vendor for ya.
But, I roll my own lamps and do not sell them.


No worry, I have no doubt that there will be several led-heads that do use commercial lamps showin' up soon.


Aloha,
Weezard

Hi Weezard

I really needed to hear your opinion, opinion of professional. It is so sad that there are so many cheaters on today´s market

I guess I will have to buy 15OW HPS ( I knew that it is not like 400W hps but I was thinking that at least it can be like 150 - 250W HPS ... I was reading a lot about LED grows so for me it is stupid when vendors is telling that it can replace 400W ).

So thank you a lot ... I will have to wait a few more years I guess

BloodyBeer

 

[Frankinsensi]

Hey BloodyBeer ~ There are only two commercial lights i would buy.
These:http://www.growledhydro.com/ 120 day money back guarantee and a 5 year warranty, which I believe is better than anyone else offers.

and these:http://www.greners.com/grow-lights/led-brand/lumigrow-es-165-led-grow-light.html

Both companies are proven.

 

[unclefishstick]

i dunno,it looks like i am on track to get somewhere in the 8 oz range from my 205w LED,as far as im concerned that will pay it off in my mind,indeed,i have only gotten a half pound from a 400w HID a few times,considering i could cram this light practically any spot it would fit and have a near zero hassle grow is enough to convince me...

 

[Weezard]

A noteable endorsement!

A noteable endorsement!

i dunno,it looks like i am on track to get somewhere in the 8 oz range from my 205w LED,as far as im concerned that will pay it off in my mind,indeed,i have only gotten a half pound from a 400w HID a few times,considering i could cram this light practically any spot it would fit and have a near zero hassle grow is enough to convince me...

Dere ya go, Bloodybeer.
Uncle knows what he's talking about.
A good 200W. LED will outproduce a 150W. HPS by a wide margin.

Aloha, Uncle

Good t'ing I'm not da "Itolyaso" kine guy, ya?
You grows are mouthwatering good, brah.

Grow-on!
Weeze

 

[smokefrogg]

well today i received a few more of the budget sunshinesystems glowpanel 45s, i know these are not super amazing but for my purposes they have been working

pragmatically speaking, these have been kicking some ass as supplemental lighting hanging vertically splashing led lighting onto the side of my flowering plants, a 400 watt hps on top showering down onto the plants

 

[unclefishstick]

Dere ya go, Bloodybeer.
Uncle knows what he's talking about.
A good 200W. LED will outproduce a 150W. HPS by a wide margin.

Aloha, Uncle

Good t'ing I'm not da "Itolyaso" kine guy, ya?
You grows are mouthwatering good, brah.

Grow-on!
Weeze

if i have any complaint its the footprint,but like i said,anything over 4 ounces from a 32x32 screen is a win in my book,i know plenty of people who only smoke an oz a month,a light like this would be ideal for someone like that,for large scale commercial spaces,not so much,but the casual home grower,this is an ideal match..

well today i received a few more of the budget sunshinesystems glowpanel 45s, i know these are not super amazing but for my purposes they have been working

pragmatically speaking, these have been kicking some ass as supplemental lighting hanging vertically splashing led lighting onto the side of my flowering plants, a 400 watt hps on top showering down onto the plants

thats one of the fun things about doing this,its your garden and you get to do what you want!!

 

[blimblom]

well I thought it wouldnt fit this thread, but as you are talking about readymade LEDs, have a look at this. It is a site like dealxtreme and it claims 120W for 190EUR, which is quite cheap.

even if they use older bins, those of you who dont want to tinker with making your own lights, maybe it is worth to try.

from the pictures, they seem quite ok (not 10mm stuff or anything), but who know for real??

 

[Weezard]

Not it!

Not it!

well I thought it wouldnt fit this thread, but as you are talking about readymade LEDs, have a look at this. It is a site like dealxtreme and it claims 120W for 190EUR, which is quite cheap.

even if they use older bins, those of you who dont want to tinker with making your own lights, maybe it is worth to try.

from the pictures, they seem quite ok (not 10mm stuff or anything), but who know for real??

Aloha, BlimBlom

Since you asked.
They quack like junk to me.
Roughly, it's a square UFO that should sell for about $150 USD
There is a conspicuous lack of factual information on that page.
"NASA colors?" Tsk!
Same folks also sell 14W. "China panels".
Would not touch it with a stick.

JMO.
Weezard

 

[blimblom]

yes weezard you are right about not having any proper information on what kind of LEDs they use, or how intense they are. I think they have a 8:1 R:B ratio.

What struck me as interesting is that they dont seem to use th usual 5-10mm leds and if they really are 1w leds, they are not that expensive for a ready made set.

Of course as you say, it doesnt smell like a solid offer from the data they give.