Drowning in conflicting plant graphs - help! (LED)

[RackitMan]

Still trying to design my LED light through clear understanding and not just mimicking.

There is one photosynthetic response curve that shows yellow light has more effect than blue light and that green, while lower, is almost as useful.

Other articles say green light may stunt plant growth and that yellow is not much more useful (despite the huge success of HPS).

Then there is the photosynthesis action spectrum showing that violet/purple light (400nm) has the highest absorption peak followed by deep read at 670nm with a huge dip in green and yellow - yet almost all LED mfgs stress a huge red to blue ratio.

Then there is the chlorophyll absorption graphs with multiple peaks and lesser carotenoid absorption peaks. (Seems this may be due to invitro rather than adult plant testing).

Then there are articles stressing the importance of balanced and 'correct' spectrum (CMH) and others stressing sheer photonic output (as seems to be the case with HPS). Another case is where a standard fluoro outperformed a plant grow fluoro due to higher photonic output. (Pardon if that is the inaccurate scientific descriptor).

I have read and studied many hundreds of pages on the internet and at the local library and while I have gained some understanding am in some ways more confused than when I started.

Is this merely a case of totally different aspects of plant physiology (or different plants) being studied or is it a case of incomplete information?

RackitMan Reviewed by RackitMan on 05-03-2010. Drowning in conflicting plant graphs - help! (LED) Still trying to design my LED light through clear understanding and not just mimicking. There is one photosynthetic response curve that shows yellow light has more effect than blue light and that green, while lower, is almost as useful. Other articles say green light may stunt plant growth and that yellow is not much more useful (despite the huge success of HPS). Then there is the photosynthesis action spectrum showing that violet/purple light (400nm) has the highest absorption peak Rating: 5

[GetThisOrDie]

Whats up?

I have grown with LEDs but I definitely dont know much about the science side. You mention the blue and deep red with mfgs stressing large red ratios... From what ive read the plants use more blue light in VEG and red light in FLOWER. We are all about the flowers (at least I am :stoned so a light that produces more reds than blues is what is best for flowering.

Also I know HIDs like an HPS give off a huge spectrum of light but the plants benefit mostly from the reds given off. Same thing with MH bulbs and vegging. So a graph depicting the spectrum output of an HPS will show all sorts of colors but you only need to focus on the reds and blues. Or so ive read...

I hope all those pages of LED stuff I read (and mostly forgot! lol) were correct so i dont give you misinformation.

Just trying to help in any way I can.

[mrnobody]

Plants need a full spectrum. For twenty years we have been depriving our plants of love we could give it. You dont see them using HPS in the cast research grows. it is a combination of induction (plasma) and high end led where certain plants thrive under certain wavelengths. The science is restricted so it is a test for us all. This is no bandwagon anymore and its probably time we started to publish all we can in regard to new lighting. Personally i will be growing under Plasma lighting with added leds, It will give me a total full spectrum like the sun on earth and on top of that i am ramping up on the blue and red, obviously vital for veg andflower. The plasma units are actually cheap in comparsion to generating the same light with LED.

[GetThisOrDie]

Are you going to log the plasma grow?

I totally agree that all knowledge should be posted here for everyone to benefit from it.

Got any sites selling plasma stuff? Im always curious to see new tech.

[bigsby]

mrnobody would you discuss your induction light a bit more. I've done some reading and understand that similar to LEDs, there are a range of manufacturers pumping out bulbs with varying spectrum output. Have you narrowed in on a manufacturer / distributor? What specs do you look for?

[mrnobody]

I live in the Uk and have a specialised supplier here I have been using for LEDS for the last couple of years. His new products have the LEd built into them RED/BLUe and then full spectrum white light. The most powerful model is 500watt but only draws 250 and is about 20 times brighter than a HPS 600watt. There are few suppliers around but i think in the states Lumatek is leading the way and there are a few grow logs around on other sites showing these in action.

I will be doing a Plasma log as I should have done with the two I am doing at the moment with an LED/HPS split. (all vegged in LED though) Four weeks away from finishing on 55 Armageddon that look stonking, and 2-3 weeks away on 100+ Lowryders, The AK48 looking ridiculous and certainly no lowryder!

I have spent all and everything on this setup so cant afford a new camera at the moment, hence no grow log. There are grainy photos on another link.

cheers

[RackitMan]

The most powerful model is 500watt but only draws 250 and is about 20 times brighter than a HPS 600watt.

Try to make sense. A 500 watt light draws a minimum of 500 watts.

Twenty times brighter? Do you just make stuff up? :wtf:

[demoreal]

when you build your LED will you post up what you did. I am thinking of building one after summer. Start a build your own LED thread. Or I will. No, you do it. I am too shy.
peace. good luck with it.

[headshake]

i agree that plants need a full spectrum light. just because there are peaks at certain wavelengths doesn't mean that there is nothing else but those peaks. nothing beats the sun, and the sun encompasses the complete spectrum. the specific wavelengths were more a rush to market approach IMHO. white LEDs are more expensive than the others (again, i know you know your shit, just puttting it out there). and there's still the fact that they are really blue LEDs with a Yttrium Aluminum Garnet phosphor layer. but white LEDs are considered as covering the entire spectrum.

i think ones best bet with proceeding in the LED realm, would bo to make a lighting rig that had all possible wavelengths on the market with each having it's own dimming circuit. i'm not saying it's that easy or whatnot, but i do believe that that would be a great way to start. i think we still have a very narrow understanding of all the wavelengths and their relation to plants. not everything in a plant comes from two (or four) specific wavelengths, so two (or four) wavelengths are not the answer. again, all opinion here, and by no means an expert. let us know what you decided and i most definitely will be following along.


-shake

[demoreal]

I second what headshake said.
They make some LED's with a dimming switch. I have only seen the ones with adjustable red and blue.