Understanding what light is in plants and photosynthesis. Questions

Hello,

I am writing this question because I have a hard time, trying to figure out how many % of the photosynthesis in cannabis is coming from the different plant pigments

What I am sure of is:

chlorophyll a 430nm 662nm dual peak
chlorophyll b 453nm 642nm dual peak
phycoerythrin 590nm single peak
phycocyanin 625nm single peak
Beta-carotene 450nm 480-485nm dual peak
(please correct me if I am wrong)

This means that the plants have 8 different wavelengths of light where they absorb a high % of the light and this results in higher yield pr Watt, compared to using a lamp lighting over the whole spectrum.

As I understand it, I need to mix the different wavelengths to activate all the different pigments. But how many of each is a puzzle to me. Also been reading some articles that 24% green light is a good thing boosting photosynthesis a whole lot. I dont know why.

I refuse to pay 25$ for an 7 page article on some site (again)(It brought me more questions than anything else)

I am thinking of making a "diy LED lighting setup" but I am very confused which Diodes to use (Except the 661 nm 10W or 15W ones from LEDengin (Showa Denko)). The part putting them together I have a very good friend that can help me with.

The reason I chose LED is that I have a walk in closet (1x3x2 Meters) with no windows nearby, in my appartment and I want to be as stealthy as I possibly can. Low heat signature (meaning that I dont need to pull a lot of ducts for ventilation) and low electricity bill - I was going for MAX 500W in total - were the real selling points for me. That I can have an "isolated" room that only needs CO2, nutrients, and some grooming to work. The rest is timers and maintenance.

Thank you for your time and replies.

I know that this LED vs HPS has become a case of religion for some people. But for me this irrelevant. A high electricity bill and fans and ducting will make me busted in a very short while. And also the missus will not allow it So please keep HPS VS LED out of this

Also - If you have the homepage that will answer me my questions - your help will be greatly appreciated !!!

Best regards

"As I understand it, I need to mix the different wavelengths to activate all the different pigments. But how many of each is a puzzle to me. Also been reading some articles that 24% green light is a good thing boosting photosynthesis a whole lot. I dont know why."

This is a logical error... Plants are green because they reflect green light. Thus, green light is not absorbed by the plant. 24% green light will just waste money and lights. The primary spectrum's of red and blue are the most beneficial to plants. You should read up on the light spectrum of HPS (flowering lamps) and the spectrum produced by MH (vegetative lamps) to get a better understanding of what make a plant flower.

This is a logical error... Plants are green because they reflect green light. Thus, green light is not absorbed by the plant. 24% green light will just waste money and lights. The primary spectrum's of red and blue are the most beneficial to plants. You should read up on the light spectrum of HPS (flowering lamps) and the spectrum produced by MH (vegetative lamps) to get a better understanding of what make a plant flower.

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Thank you for your reply - but ive read on numerous pages that state that adding 24% green light will boost yield substantially. buuut why?!

Limiting any grow light to just red and blue light would lead to poor results, since plants also use most of rest of the visible spectrum, though in lower amounts. NASA’s Biological Sciences team at the Kennedy Space Center has done extensive research on this subject: a 2006 paper published by the International Society of Horticultural Science documented improvements in lettuce yields when 24% green light was added to LED grow lights that otherwise produced only red and blue light. Including light in the yellow-green spectrum also helps to visually restore green color to plants, making them look more “normal,” and makes it easier to identify garden problems such as nutrient deficiencies or pest attacks. This combination also makes it easier for gardeners to work in their gardens.

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This is the first link about 24% green, but there a very many of them, but all of them very techical and hard to understand. So an easy explanation would be very nice - but this is not my primary question.

I am very well aware of the whole "blue for vegging" "red for Flowering" but I think there is a lot more to it than that.

What wavelengths to use I stated in the scheme at the top, but how many of each - and "advanced" pointers would be very very nice, and greatly appreciated.

Thank you for your reply

I'm sure there is a lot more to it than that. Of course, agriculture is a science, so there is always a "better way" to do something. However, if you just take a look around this forum, you can see for yourself what most people can with with just a MH and HPS light. they can do some incredible things! Why make it more complex than it needs to be?

<stealthgrowing> said:

I'm sure there is a lot more to it than that. Of course, agriculture is a science, so there is always a "better way" to do something. However, if you just take a look around this forum, you can see for yourself what most people can with with just a MH and HPS light. they can do some incredible things! Why make it more complex than it needs to be?

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I want help to find out what lights to use for my DIY LED light. That is more complex than Blue for Veg, Red for flowering.

So I ask for help, because it IS complex and help would be very appreciated.

Also, please dont go HPS VS LED.

The reason I chose LED is that I have a walk in closet (1x3x2 Meters) with no windows nearby, in my appartment and I want to be as stealthy as I possibly can. Low heat signature (meaning that I dont need to pull a lot of ducts for ventilation) and low electricity bill - I was going for MAX 500W in total - were the real selling points for me. That I can have an "isolated" room that only needs CO2, nutrients, and some grooming to work. The rest is timers and maintenance.

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The missus will not allow it

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This is why - mostly, need to stick it in the closet and forget about it!

ahh, but you cannot just forget about plants growing in the closet... you still need to replenish the air in the closet with fresh C02 on a regular basis. Although I agree with secretive dope growing and have no qualms with hiding it from a woman that happens to live in the same house, I know that you will not be able to just set it up in the closet and forget about it. It has to be watered and tended to. Those LED fixtures must also produce heat. No light is without heat. Have you considered doing a stealth cabinet grow?

Yes, I have made it too, Mylar on the walls, combined NFT/AERO, just need controllers for CO2, and timers. And the bloody lightning done.

She isnt unaware of my plans - but all sorts of ducts, hot lamps and ventilators isnt something she thinks is cool mostly because the room is placed in a f**** place, with no windows nearby, so air needs to be pulled for ever and ever, via ducts and stuff. And this will look like crap - so I promised to keep it "stealthy". Also, its an appartment. If I start using 1000W - 1300W more on 12 hour basis, it will be noticed.

But I have sorted this out well. I need help with making the lamps - this is going way off topic

Shit man, I used a 400 watt T5 array and a 400 watt HPS in my closet at my last apartment for 6 months and nothing happened. Just pay yo bill! Ya this has gone off topic a bit. If you are doing a DIY LED then just build it with equal parts of Red, blue, green and yellow LEDS. I would place special emphacis on the red LEDs if I were building this myself. So it could go something like this, 200 - 1 watt RED LEDs - 100 - 1 watt BLUE LEDs - 100 - 1 watt YELLOW LEDs and 100 - 1 watt GREEN LEDs. Now you have a 500 watt LED fixture.

anyone got any really usefull information? (not that stealthgrowing wasnt helpfull, but my question is still unanswered )

Like a link where I can read more, or anyone with experience to what works - and what doesnt?!

Basicly, how to put together an LED lighting system so it will yield acceptable.