Blue light after 'dark'?

[metalhead419]

not to sure on this one but i will take a guess and say, no. There wont be any benefit. Plants depend on both red and blue light to photosynthesize properly, and blue is mostly just for internode length. Probably would make your plant hermie or maybe just make it do some crazy shit none of us have ever seen. Just my opinion. Im sure i could ramble on a little more, but i dont think i would be telling you anything you dont know, lol. Try it, and let us know, definitely an interesting experiment.

metalhead419 Reviewed by metalhead419 on 05-18-2009. Blue light after 'dark'? Has anyone here tried using pure blue light (LED or actinic fluoro) during the 'dark' or night phase when in 12/12 light cycle to keep photosynthesis going without interrrupting the flowering phase? I have one of the newer 50 watt blue LED panels and may give it a try, but would like to get some feedback first. Rating: 5

[DreadedHermie]

16 hours of blue(ish) light, and upwards, is generally called a "veg room." . . . . . The idea, of course, is "not" to get flowers.

pure blue light (LED or actinic fluoro)

Blue led vs. Actinic fluoro is apples to oranges. Well, maybe kumquats to oranges. Compare the spectral graphs. LED = scalpel. Fluoro = shotgun.

And in this dirty world, nothing is "pure".

To the best of my knowledge, 12/12 red light signals the plant to flower whereas blue light does not trip flowering on or off.

Do you recall where you got this information? I'd double check it. 12 / 12 @ 6500K (some actinics are not so far from this) will induce flowering quite effectively; I've done it.

If you're got spare harvest to experiment, try it and let us know. But if you're growing needed medicine (lots of people on this site are, that's why I butted in here, sorry...) or for other reasons can't afford to mess up your grow, I'd research this a bit further before risking your success. Either way, good luck! :thumbsup:

[the image reaper]

correct, the flowering onset is triggered by the hours of light, the red spectrum just helps flowering, by imitating how the Fall sun's wavelength changes as it lowers on the horizon ... I vegged and flowered for years with only blue lights (not knowing, red would have been better) ... but, why you would want blue light during flowering (after you know red is more effective, is beyond me) ... either way, best of luck to ya :smokin:

[RackitMan]

At least newbie Ed Rosenthal understood and now recommends 24 hours of blue LED throughout the entire grow cycle.

I am amazed at the close-mindedness and lack of understanding of cannabis photoperiods or real attempt to understand something new.

[the image reaper]

piss on Ed Rosenthal, he's a clown :wtf: ... his fame came as a result of his partnership with Mel Frank, the 'botany brains behind their books' ... regardless, sounds like you know more than us closed-minded folks, anyway ... happy growing ...

[oldmac]

At least newbie Ed Rosenthal understood and now recommends 24 hours of blue LED throughout the entire grow cycle.

I am amazed at the close-mindedness and lack of understanding of cannabis photoperiods or real attempt to understand something new.

Hey RackitMan, could you please supply me with a reference to where Ed Rosenthal now recommends 24hr blue LED throughout the entine grow cycle?
I started searching and have been unable to find this, I really would like to read it all in context to better understand what he is saying and any reasoning behind it.

As to understanding of photoperiods, let me show you by correcting IR's statement (and other's belief) that "flowering onset is triggered by the hours of light...". This is wrong, the amount of light or duration of photoperiod has no effect on flowering. It is the amount of dark period that determines when a plant flowers and if it stays in flower. During the dark period certian hormones (and enzymes) increase in the plant, when they reach a certian level they act like a switch to trigger the plant to go into the "sexually mature" stage (flowering). Aprox 8hrs or less of dark means the plant will stay in the "immature" stage or vegative phase, aprox 10 or more hours of dark and flowering will occur. BTW; the hours of dark to get a plant to trigger and hours of dark needed to keep it in flower can be different.

I try to learn something new everyday, and am always open to new ideas...hell I've been experimenting and using LED technology for over 2 years, in spite of hearing "led's don't work" from people the entire time. Share some additional info, inquiring minds want to know!