LED grow lights... input please.

[craftsmaster]

A standard four-foot unit with two 40-watt bulbs -- or tubes -- illuminates an area about eight inches in width. A bright but overcast day measures about 1,000 foot-candles. By contrast, a bright, sunshiny day generates about 10,000 foot-candles.

Contrast this to fluorescent lights. At six inches from the source, you'll be receiving about 700 foot-candles. And when you're a foot from the light, the foot-candle measurement drops to 450.
__________________
Carmel Santos
CEO of Herb Gardening Guide
Growing Herbs in Pots
The Australian Guide to Herb Gardening

[khyberkitsune]

"Contrast this to fluorescent lights. At six inches from the source, you'll be receiving about 700 foot-candles."

With not only incident light meters, but typical garden foot-candle meters, I've never had lower than 1,200 foot candles from T5HO Fluorescent one foot from any T5Ho light, banked or individual.

And the highest I've seen is 2,500 foot candles from the same distance in laboratory conditions.

[krazyken]

Man. I'm glad I found this thread. My greenouse is being built now, but i don't want to use ballasts and deal with cooing units, etc. LED lights might be exactly what I need. Doing lots of research into it now.

Thanks.

I have developed a great ratio after discussions with Kyber. Ratio's of 7:1:1 will not give max yields or trichome development. Most peeps lights are generic high production lamps that are overly priced. Shop around and talk to the sellers by telephone, and ask questions. There are only 4 peak spectrums needed, and orange and white are not one of those.

Ken

[smokewhat1]

I'm probably gonna put together a DIY tutorial if anybody's interested in building their own light. Let me know, Hermie.

I have been trying to wrap my head around all of the things needed to make my own LED light system. If you are going to make a tutorial...I'm in!

[sheets91]

My spouse and I are arguing which is best. Please respond with examples

[brynpav]

On that site it says "We do not offer anything bright enough for general household lighting. LED bulbs are used for accent and other low light applications." They can't be appropriate for growing.

cannabis receptors reach saturation @ 1500-1800 micro-moles and will disregard any light outside the wavelength it is looking for at that particular time within it's growth cycle.

therefore the importance of quality and quantity of PAR light at the receptors cannot be understated. One of the things that I found LED's had difficulty achieving was, as nature would provide, photomorphogenesis wherin the spectrums, especially IR levels, would not be so narrow that the full yield inhibited by lack of enough energy in red and far red levels without having to create an LED lamp/driver combination that would rival HPS in wattage while being 4 x the price and needing 2 or 3 of them to cover the same area.

any grower having compared yields between the most advanced LED and the simple HPS will attest to the compromise in yields. So while we all would like to find the holy grail of energy efficiency, lamp life, PAR spectrums there really is a much simpler way to go about it.

[khyberkitsune]

"any grower having compared yields between the most advanced LED and the simple HPS will attest to the compromise in yields"

Which is to say, EXACTLY NOTHING.

Those other 'tests' are done by non-scientific, non-professional garage growers that are using a mass-produced copy of outdated 90s LED research.

Grams per kilowatt-hour, LED wins all day every day, across every crop ever tested in a truly professional and scientific setup.

Like this:



To this:



To this:



All day, every day.

[Weezard]

Welcome Brynpav;

"any grower having compared yields between the most advanced LED and the simple HPS will attest to the compromise in yields"

I disagree!
You sound well educated but appear to be mis-informed;

[attachment=o259848]
The middle "clone" is sun-grown.
Granted, all three are crappy, but that's my failing.
I'm not a good grower, but can't fault the leds.

[attachment=o259850]

Led buds in forground, sun buds in back

[attachment=o259851]
2 more weeks or so to go.


[attachment=o259849]
Out for a "tan" just before the chop.

Perhaps more research is in order?

"there really is a much simpler way to go about it. "

Intrigued, please expand on that.

Aloha,
Weezard (A non-professional garage grower):rastasmoke:

[brynpav]

Welcome Brynpav;

"any grower having compared yields between the most advanced LED and the simple HPS will attest to the compromise in yields"

I disagree!
You sound well educated but appear to be mis-informed;

[attachment=o259848]
The middle "clone" is sun-grown.
Granted, all three are crappy, but that's my failing.
I'm not a good grower, but can't fault the leds.

[attachment=o259850]

Led buds in forground, sun buds in back

[attachment=o259851]
2 more weeks or so to go.


[attachment=o259849]
Out for a "tan" just before the chop.

Perhaps more research is in order?

"there really is a much simpler way to go about it. "

Intrigued, please expand on that.

Aloha,
Weezard (A non-professional garage grower):rastasmoke:

I'm a private grower having completed 2 grows now where I'd converted from HID to induction and the yields have been on par @ 300 g/m for the HID with a 60% savings in connected load. These are significantly less expensive to purchase and get up and running compared to the LED arrays as shown in these attachments.

Have you seen how healthy plants will veg under a 100 watt induction? it's remarkable. I currently have 8 of the 400 watt inda-gro lamps for flower and bud and really don't have a complaint I can site.

I have heard some horror stories about induction as well and initially only went in with an order of 1 400 and 1 100. I've heard the problems that people have had is that when they try and use these as an IP65 rated fixture which as growers we don't need that rating and the temperature within the fixture and our environments can create thermal overloads. But even so I had only heard of this occurring on the mland brand direct out of China.

I'm not here to dismiss the potential of LED for grow. I hope it does deliver but I've not seen the success from these lamps that the manufacturers I dealt with; UFO & HTG had claimed. I really had hoped they would lower the loads and still maintain yields but both of these fixtures had led failures within 2 months of having installed them. So far the inductions have been hassle free. :rastasmoke:

[knna]

cannabis receptors reach saturation @ 1500-1800 micro-moles and will disregard any light outside the wavelength it is looking for at that particular time within it's growth cycle.

Plants, cannabis included, uses all light into PAR at similar efficiency. They dont disgregard any specific wavelenght into PAR. Thats is an absolutely well proven fact.

therefore the importance of quality and quantity of PAR light at the receptors cannot be understated. One of the things that I found LED's had difficulty achieving was, as nature would provide, photomorphogenesis wherin the spectrums, especially IR levels, would not be so narrow that the full yield inhibited by lack of enough energy in red and far red levels without having to create an LED lamp/driver combination that would rival HPS in wattage while being 4 x the price and needing 2 or 3 of them to cover the same area.

Ive found photomorphogenesis to be way better controlled with LED light than when using any other type of light.

You decide exactly how many UV, IR and far red you provide your plants, allowing you to tune the lighting to the exact requeriments of a specific plant. Of course, if you do it bad, you can get worse results, but its not a limitation of LED lamps, but people misdesigning them or growers using them the wrong way.

Using more than one point source is not a limitation at all, but a large advantage. Improves penetration in typical indoor crowded canopies, achieves even light distribution, which enhances light efficacy. Avoid hot spots and areas underlit, typical of HID growing.

any grower having compared yields between the most advanced LED and the simple HPS will attest to the compromise in yields. So while we all would like to find the holy grail of energy efficiency, lamp life, PAR spectrums there really is a much simpler way to go about it.

I would agreed if you have said "many growers" instead of "any grower" and skipped the "most advanced" lamps statement. Many crappy LED lamps out there, specially a pair years ago.

People tricked for dishonest LED sellers to believe they can get the same yield with 100W of LEDs than with 600W HPS (which is impossible) got dissapointing results.

But growers using good designed LED lamp systems are getting similar yields using near half watts, forgetting heat issues and getting way higher productivities (yield per input watts).

I have heard some horror stories about induction as well and initially only went in with an order of 1 400 and 1 100. I've heard the problems that people have had is that when they try and use these as an IP65 rated fixture which as growers we don't need that rating and the temperature within the fixture and our environments can create thermal overloads. But even so I had only heard of this occurring on the mland brand direct out of China.

Ive heard too horror stories about induction lamps reliability. Ballast heat is often underlooked by designers. And its clear than 95% induction lamp systems have a lower expected life for the ballast than for the bulb itself. Reliability stands for the whole system, and its very hard to find long term reliable induction lamps (reason of their limited market penetration).

But letting apart that topic, its true that its easier to get a good perfomance from induction lamps than from many currently on sale LED lamps. All induction lamps have similar efficiency, while LED lamps vary strongly from one to the another.

But perfomance gain of induction lamps is limited over HPS. Its a technology with very little improvement margin (except on reliability). Little spectrum advantage, similar energy efficiency, same problems with the need of using big lamps far from plants. Big bulbs that need to use big reflectors, often little efficient.

They work very well in veg. But LED lamps do it still better. Have you seen what 100W of good LEDs can achieve on veg? We are using it on 1 sq meter very sucessfully, replacing 400W MHs with 120W of LEDs or so and getting better growth rates yet