A Curved Shaped LED Light

tags420 said:

Response and absorption are different. Stardust schooled me on that

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Yes, response is the effect of absorption, which means if you provide 10% intensity in the yellow area it responds much better than other spectrums. It doesn't mean adding more yellow light is better though. When building a light we care about matching the absorption spectrum, not the response.

There is more to that low absorption portion than most think.

read this you might like it and show you more where I am coming from.
http://www.heliospectra.com/sites/www.heliospectra.com/files/field_page_attachments/what_light_do_plants_need_2012-10-05.pdf

I know the goal is matching the peaks for most efficient use. I never said adding more yellow was the goal...just that there is a reason why even with the highly yellow hps, they grow fine.

I agree, there is much more to light than what graphs can show... and that is where we are at today, trying to figure out the ideal intensity of different spectrums to maximize the light for plant growth while minimizing power consumption. Even after studying light for the past 20 years in various hobbies I don't have all the answers. I am trying to put the puzzle together just like everyone else.

tags420 said:

There is more tho that low absorption portion than most think.

read this you might like it and show you more where I am coming from.
http://www.heliospectra.com/sites/www.heliospectra.com/files/field_page_attachments/what_light_do_plants_need_2012-10-05.pdf

I know the goal is matching the peaks for most efficient use. I never said adding more yellow was the goal...just that there is a reason why even with the highly yellow hps, they grow fine.

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That is a great link, thanks for posting it.

IMO the MH approach is the 'shotgun' approach.. but it far from the most efficient. Meaning if you push 600w of MH light to a plant it will grow fine (as proven repeatedly in grow logs). If you are putting out 90% intensity in the yellow spectrum with MH but the plant can only use 10% of it, the remaining 80% is just wasted. The LED approach is more like a rifle than a shotgun. We have proven that over and over in the aquarium hobby. A 400w MH, while does work fine growing corals under water, can't compare to using spectrum specific LEDs in terms of power usage. I can grow corals just as good using 50w of LED light in the proper spectrums than with 540w of MH and T5HO light, which to me proves how inefficient those lights are and how efficient LEDs are, even when the MH bulbs are designed for that hobby and put out more blue than your average MH bulb. Plus in the aquarium hobby I had to replace MH bulbs every 6 months, and T5HOs every 9 months. Bulb replacement in 1 year cost as much as the LED light I made, meaning my LED light paid for itself in less than a year, and every year since then I have been making $ by means of a much lower electric bill (my bill went from $400-$500 a month down to $80 a month).

In the end it comes down to $. If you have more $ than you know what to do with and want something simple that will grow plants, go with MH, but if your goal is the save as much $ as possible on the electric bill while providing comparable results, LEDs are the winner. Plants and corals have a limit to how much they will use/grow, and if we are already reaching that limit with MH lights then LEDs are not going to grow things any better, but they can grow similar results while using a fraction of the power if designed correctly.

Isn't this a just a question of how much par per nm is getting put out? I've seen these types of readings before, I believe the tool is called a spectroradiometer or something like that? And on the subject of lumens, if I can see with my eyes that one light is more intense than the other, then the plants are still going to feel the high level of intensity, although it goes back to the spectrum, whether you are getting good intensity in the right nm's. So from what I've seen over the years is that high intensity even with wasted nm's (hid) will out produce low intensity w/ just red/blue for example (early model leds). Now that leds are just as or more intense, and we can target specific nm's, the results are nothing short of great. Its just a matter of getting intensity & spectrum married together. A bit of rambling and rehashing of whats already been said, but yes, give me intense light anyday to grow big dense buds, but also give me efficiency and proper spectrum. I love leds because you can get the best of all three. So what exactly are we trying to figure out here again?

puffenuff said:

So what exactly are we trying to figure out here again?

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LOL, nothing really, it seems we are all on the same page and just talking in circles.

So with your years of experience you would say that lenses/optics r like a must have feature?

For the purpose here, yes, optics are a must have. On my algae scrubber, optics are bad as it ends up frying the algae due to photo-saturation from being too close (and no way to pull them back).

JMD said:

Lumen doesn't matter - lumen is a way to quantify in relation how well the human eye sees it. Lumen and PAR is like oil and water.. both are liquids, but they are miles from each other.

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Sorry but that's incorrect............I understand that you look at graphs and see those chlorophyll a/b peaks and hps is FAR from being optimal, but then why is it still used by 95% of greenhouses/professionals?? The bees don't even like the color of HPS, and Dutch growers still use it!!! Because a 1000w gavita HPS will still out-yield anything.

That's why we are here no? to grow the most bud per watt used indoors................aquarium industry is different, it's about keeping the ecosystem happy ! NOT about producing yield.

A 150w hps (135-140lm per watt @ 2200k) 16000 lumens will outperform EVERYTIME a 150w CFL (52-60lm per watt @2700k)7900lumen bulb.......why??????????????

We have been discussing the best led ratio/spectrum for cannabis for over three years now and we got NADA..............So it's time just to follow in the footsteps of HID and blast them with VERY high lumen per watt "white"........maybe a slight shift to the red like CMH

<<<<this is where we want to go, 2-400w cmh retrowhite(pinball wizard's grow), high lumen per watt and a decent spectral output

PSUAGRO. said:

That's why we are here no? to grow the most bud per watt used indoors................aquarium industry is different, it's about keeping the ecosystem happy ! NOT about producing yield.

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100% false, yields mean MUCH MORE to aquariums than any MJ grow, you want to know why, I can make 100x more $ selling corals than I ever could selling weed, and I can do it legally. There is also the satisfaction of being able to grow those types of corals, because they are very difficult to grow compared to a weed.

When you can get $200 for a 1" red colored stick and you can grow 12" worth of sticks a month, which one pays more? That is just 1 coral, I can grow 100 different types of corals in a 4'x2' area.
http://www.exoticfrags.us/corals.php?&c=456

no shit .....it was an assumption, what are the light requirements for corals? Compared to cannabis?


I really have no idea about the aquarium industry ........I was talking more about household aquarium lighting demand a/hobby use, not profit.

For the purpose here, yes, optics are a must have. On my algae scrubber, optics are bad as it ends up frying the algae due to photo-saturation from being too close (and no way to pull them back).

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I wonder if u or some one else has experience with simply using a reflector in a good angle of the led fixture with something like matte white, i wonder how the improvement to "no lens" would be. Or have u tried that measurement with no lense in a "reflective" area, like a box or something. I have only about 130Watts for about 50x50cm, but walls r white.
Also i made a 30Watts of white cree for just keeping a mother (that i dont have yet) alive.

Should i make a journal with all specs about my poor first attempt of growing mj, or would that be just some effort wasted because no one cares? considering ur r all like going large with ur 400-600-800Watts and so on. But i really would like some input on what i can improve :-/ , maybe i should create a topic asking this, problem is its "newbie at work" and "newbie led" hehe but maybe minus and minus equals plus
dont want to break rule #1 -noobs tend to spend too much on first attempts without having aquired the neccessary skills

PSUAGRO. said:

no shit .....it was an assumption, what are the light requirements for corals? Compared to cannabis?


I really have no idea about the aquarium industry ........I was talking more about household aquarium lighting demand a/hobby use, not profit.

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Lighting requirements for SPS corals are about 2x as much light as you would need to grow cannabis. One of the reasons is you have to penetrate up to 2' of water which really reduces the intensity, then corals are much more light demanding than any plant. Cannabis growers seem fine with PAR numbers in the 800-1000 range (400-600w MH), where as with corals we try to break the 2000 PAR range.

lax123: Using typical MH reflectors with 3w LEDs doesn't help much, but I seen others use them with 50w and 100w multichip LEDs. Bottom line, it isn't nearly as good as using secondary optics at the LED, but is better than nothing if you have a spare reflector laying around. I wouldn't buy one for that purpose though because optics for 50/100w LEDs are cheaper and better than most MH reflectors (which are just too large to do the job efficiently). Check out this thread to see what optics look like on a 100w DIY LED light.
http://www.reefcentral.com/forums/showthread.php?t=2128756&page=4

I want 2000umol indoors if I can get it. The 700-800umol is what universities and whatnot say is the requirement for high light crops like tomatoes. But MJ growers and anything that grows outside in full sun says it will take lots more. I grew up/learning outdoors where I(like everyone) get 2000umols everywhere. When I first went indoors I used 1000w'ers and they were great honestly and do about 1000-1500umols, but not outdoor obviously. And paying $0.30/KwH get's old quick even with just 2kw. So I dialed back to 600's and also began to get into led's. That was 3 years ago now and I am always coming back to getting closer to the sun's 2000umols to get higher yields. Yield comes down to the amount of photons falling on the canopy and using more efficient wavelengths only makes up for so much.

And I don't want to sound like I think spectrum is not important...it is really important. And does things for the plant other than yield, like quality and general health of plants. But it just so happens that our most efficient and powerful lighting source, led's, can also mimic the perfect plant growth spectrum too.


Hey joe...do the corral themselves have a high light requirement or is it the fact that they have to penetrate water depths.

There are 3 general types of corals, soft corals (low light, no skeleton), LPS corals (medium light, calcium skeleton but a few large polyps), and SPS corals (high light, calcium skeleton and thousands of small polyps). It is a little of both to answer your question.. 12" deep under water with a general white light that puts out 2000 PAR light at the surface will only put out about 800 PAR, so over 1/2 the light is lost in the first 12"... go another 12" and you are now looking at 200 PAR, a 90% loss. We try and mimic the sun at the surface of the water for intensity just like in nature, which is where the 2000 PAR number comes from (which you obviously know), but we also use a lot more blue spectrum for both our preference of making the tank look like the ocean as well as added penetration of light. If you make a light that is heavy in blue and 2000 PAR at the surface, it will be closer to 1400 PAR @ 12" underwater instead of 800 PAR because it penetrates better than higher spectrums.

To get even more off topic and scientific, corals themselves actually don't use light, it is the zooxanthellae algae that lives inside the coral that uses the light to convert to sugars to feed the coral. The coral gives the algae a safe place to live while the algae gives food back as 'rent'. When corals bleach, that is from the algae saying 'this place sucks to live, we are outta here'. If new algae doesn't move in quickly the coral will die.

PSUAGRO. said:

Sorry but that's incorrect............I understand that you look at graphs and see those chlorophyll a/b peaks and hps is FAR from being optimal, but then why is it still used by 95% of greenhouses/professionals?? The bees don't even like the color of HPS, and Dutch growers still use it!!! Because a 1000w gavita HPS will still out-yield anything.

That's why we are here no? to grow the most bud per watt used indoors................aquarium industry is different, it's about keeping the ecosystem happy ! NOT about producing yield.

A 150w hps (135-140lm per watt @ 2200k) 16000 lumens will outperform EVERYTIME a 150w CFL (52-60lm per watt @2700k)7900lumen bulb.......why??????????????

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What JMD says isn't incorrect
First, 1watt (luminous power) of 550nm green give 683lm
1 watt of 450nm blue give 31lm
the human eye is not a plant... and "lumens are a way to quantify in relation how well the human eye sees it" according to JMD,
I agree
Then a 150w CFL is a 100w light, that's why it's useless to compare a 150w HPS to a 150w CFL
Moreover according to what I said, you can't compare two lights with lumens if their spectrums are different

People use HPS because it's really cheap and it works
Moreover the spectrum choice is not easy when you purchase a LED unit

Is it too hard to search "lumens" in google? I don't think so
The next time you will say "that's incorrect" you should take the time to search a little


The absorption is not the only important point,
the colour ratio is more important than absorption
as instance, the big quantity of green in the HPS spectrum induce shade avoidance symptoms,

It may be true, yellow range could have a great impact on MJ flowering.
But we have no proof, or even arguments ( I mean scientific )

skyled said:

It may be true, yellow range could have a great impact on MJ flowering.
But we have no proof, or even arguments ( I mean scientific )

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Did you guys not read the whole thread???

tags420 said:

There is more to that low absorption portion than most think.
read this you might like it and show you more where I am coming from.
http://www.heliospectra.com/sites/www.heliospectra.com/files/field_page_attachments/what_light_do_plants_need_2012-10-05.pdf
I know the goal is matching the peaks for most efficient use. I never said adding more yellow was the goal...just that there is a reason why even with the highly yellow hps, they grow fine.

Click to expand...

I believe I got that link from EH.

PSU knows about par man. But has basically come down to the same thing I have. Led's are/have been lacking in actual photons being output(umols), and the higher par diodes just so happen to have high lumens too(whites for us). And that's the way they are advertised and most don't have quantum meters. Obviously I don't want a all yellow led that hits 1500umol. But lets be honest, making a near ideal in theory growth spectrum with led's is not that hard. Everyone is slightly different but they are all 10X better than the hps spectrum. So even with the worst led grow spectrum, if you could match photon output(PAR) everywhere over the whole canopy(not just center) the led should have better results. So I would like to see more actual light being matched or at lest 60% matched, cause we haven't really seen it done(specially for 600-1000 hps). Then I think we will see better yield results, while still having the far superior quality we have been seeing for years with led's.

Look at dj's grow. His buds were like a foot from his light(a51 sgs), so receiving 1000+umol and his space was not stretching the coverage of the light. So the canopy was receiving a high intensity and full coverage of umols and he killed it. Plus a great W/R spectrum they loved too.

I got pretty ripped this morning and I think I am rambling...I think led's output is far behind it's spectral superiority.

tags420 said:

Did you guys not read the whole thread???

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Yes, I did it.
I don't understand, what do you mean?