The far red thread

Discussion in 'LED and other Lighting' started by Rahz, Apr 14, 2015.

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    WeedSexWeightsShakes

    WeedSexWeightsShakes Well-Known Member

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    Rocket Soul

    Rocket Soul Well-Known Member

    Could anyone recommend me some decent far red diodes from digikey? Their search engine is a head ache.

    Want to do end of day treatment for the new led room we are setting up. It will have 2 cannopies, about 2m x 1.2m each or 4x6,5 in feet.

    Im aIlready getting some stuff from digikey so wanna get the far red at the same time to save on shipping. Looking for a simple setup, no-soldering connections and star-type diodes. But digikeys search engine is less than helpfull.
     
  3.  
    Aolelon

    Aolelon Well-Known Member

    https://www.digikey.com/products/en...g-color/125?keywords=Cree+xp-e&sort=&pv40=970 I'm unsure if they have the solderless ones with the starboard attached..
     
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  4.  
    Rocket Soul

    Rocket Soul Well-Known Member

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    Aolelon

    Aolelon Well-Known Member

    I'm unsure if digikey sells the solderless ones tbh. Rapidled does for like 3$
     
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  6.  
    Aolelon

    Aolelon Well-Known Member

    Rocket Soul likes this.
  7.  
    Rocket Soul

    Rocket Soul Well-Known Member

  8.  
    Randomblame

    Randomblame Well-Known Member


    Sure of course, lol!

    Ebay! 25$/10pcs, 601 bin, but not solderless..
    https://www.ebay.com/itm/10pcs-Cree...116845?hash=item4b23bcb4ed:g:txsAAOSwKUhZsUG5

    or solderless, 701bin, but not that cheap..
    https://www.rapidled.com/solderless-cree-xp-e-far-red-led/
     
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    Rocket Soul

    Rocket Soul Well-Known Member

    Looks like digi doesnt have what i need, will look into led-tech.de and hope for not too bad shipping fees. @Randomblame,
    4 of these per m2 should work for getting enough spread?
    https://led-tech.de/en/OSRAM-Oslon-SSL-120-Far-Red-Plug-and-Light-Star-Horticulture


    How many Umols to complete the switch to night mode, like 3000 per m2? (Reading back this thread that nr seems a bit high...)
     
    Last edited: Jun 3, 2018
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    Randomblame

    Randomblame Well-Known Member

    No, numbers are not too high!
    The website says each SSL120 diode produce a min. of [email protected] As fas as I know the horticulture series is at least 275mW, hmm!. Well, that doesn' matter much. With 4 diodes it would be 1 or 1,1PAR/w far-red. QER for far-red is ~6μMol/j so you get 6 or 6,6μMol/s PPF depending on which min. output we use, in the end it is 6 or 6,6μMol/s/m²(-wall loss).
    Let's take this 6μMol/s nevertheless to keep it simple.
    So how many seconds with 6μMol each are needed to reach 2000-4000μMols?
    333sec./5,5min. are ~2000μMols, 500sec./8,3min. are ~3000 and 666sec./11min. are ~4000μMols. Calculated with 275mW min. output it would be 300, 450 and 600sec..
    Drive them harder @700mA and you need only half the amount of time to get the same amount of far-red.

    PhyFr reacts really quick and there is no need to increase the length of the treatment, what counts are the amount of photones in this wavelength.
     
  11.  
    Rocket Soul

    Rocket Soul Well-Known Member

    Thank you for your endless helpfullness. :)
     
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    KonopCh

    KonopCh Well-Known Member

    Citizen 1212 3000K 80 CRI has enough 660nm for Emerson effect? So if I add 730nm diodes to that, I get enough for Emerson effect? And drive them (730nm) 5-10 minutes after light off for faster finish also?
    Or that COBs has enough of both nm and Emerson effect is already running?
     
  13.  
    Aolelon

    Aolelon Well-Known Member

    The emerson effect takes place at 680nm and 700nm.
    The EOD treatment is completely seperate from the emerson effect.
    https://www.reddit.com/r/Head2HeadM...red_light_the_emerson_effect_and_phytochrome/
     
  14.  
    KonopCh

    KonopCh Well-Known Member

    Some says 660, some 670, some 680... NCBI (science library, not Reddit) says it's starting at 670nm... and with far red with 680-720. Anyway, I am asking if those COBs has enough or how much watts/umols I need of each spectrum?
    I know EOD is separated.
     
  15.  
    Aolelon

    Aolelon Well-Known Member

    I understand but the paper I linked shows that far red >710nm photosynthesis greatly decreases.
    And Emerson is the one that wrote the paper, just because the guy from reddit is explaining it. The paper is in the link.
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC405990/pdf/plntphys00473-0065.pdf
     
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    Aolelon

    Aolelon Well-Known Member

    Emerson, and follow up research in the early 60's, all acknowledged that photosynthesis drops off VERY rapidly above 700nm (see Figure 1 in this paper by Emerson), and quantum yield at 710nm is typically charted around 10% or less of quantum yield at 660nm, and 1% at 720. It tails off to a negligible number beyond that. A couple people have pointed to an article from 1964 that suggests the Emerson Effect was shown at a wavelength of 721 or 730nm (see Table 1). Actually the more important figure from this paper is Figure 2, which shows the photosynthesis rapidly dropping off when long wavelength light is used, but the addition of 653nm light can counter this drop off.
     
  17.  
    Aolelon

    Aolelon Well-Known Member

    I've also read in this thread, that the emerson effect is a lot less noticeable with PPFD's above 500umol from your grow light.
     
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    Rocket Soul

    Rocket Soul Well-Known Member

    Very nice read :)

    I dont think nobody knows for sure but a few people have tried and tinkered with far red spectrum and found something they like.

    Growmau5 used 3000k 80cri and added about about 15w 660nm and 5w 730nm per m² and some blues, dont remember what or how much, and was happy with that, no major stretch on his plants.

    Stardustsailor, a very respected member who isnt really on the forum anymore recomended 2 parts 3000k 90 cri 1 part 3000k 80cri. He was using bridgelux cobs i believe.
    All this to the best of my recollection.

    Randomblame, uses a 1/3 3000k 90cri 2/3 3000 80cri i think, but ill let him answer for himself.

    Dawg i think he used farreds in order to be able to flower with 5000k cause he wanted his sativas shorter, and got some results. In the end it depends what you want to do.


    But this is only people and opinions. If you want scientific statements it gets harder. Broadening the spectrum in to the far red section seems to improve performance especially if you can control intensity and if you have, or are able to, balance of near red and far red.
     
  19.  
    Aolelon

    Aolelon Well-Known Member

    Yea randomblame is using a mixture of 80cri strips with 90cri cobs. From what I can see he is having great results. I was just going off what I read showing far red>700nm falls off pretty significantly, but if people are showing different results
     
    Last edited: Jun 13, 2018 at 1:07 PM
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    KonopCh

    KonopCh Well-Known Member

    Yea, those members are only great growers like you said. I can tell myself that I get great yield/GPW/whatever too. But as person who wants to know how things works, words like "great yield", "great results"... are not enough.

    But as you said, science is other story and I wanted to know about science. So measurable data which can be replicated hundred of times. I guess we are not there yet amd there is a lot of work to do for scientists...
     
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