Blue LEDs on 24/7?

[BrokrnEyes]

Hey guys, can anyone confirm this? The reason I ask is that I am getting conflicting information at my research for my first grow which will be using LEDs.

...Plants use blue light for certain regulatory processes and also for photosynthesis. Chlorophyll absorbs both blue and red light and uses the light's energy to power the complex process in which water and atmospheric carbon dioxide are converted to sugar and oxygen gas. Blue light does not affect the regulation of flowering.

When blue light is turned on during the dark period, plants photosynthesize but their flowering isn't affected. This results in more growth as the plants produce more sugars. Before LED lights it was difficult to create a pure blue light. Instead, most of the time other spectrums were filtered out, which can be an inconvenient process. Try using between 20 and 40 watts of mixed blue light per 1000 watts of regular light. I have done only initial experimentation with this so test this in a limited way first. I suspect that the additional light is an efficient way of increasing total yield...

Source: Ed Rosenthal's Marijuana Grower's Handbook

Am I correct in assuming that the article section is saying that blue LED light can be left on a plant 24/7?

 

[Papageno]

This is a religious debate. There are great reasons to go 18 on 6 off for veg but there is a ton of data that shows just go 24 hours on for veg. There are chemical processes happening at night that aid growth and are nice to have when they wake up but Ed has done more research on this than anyone and he say just go 24hrs.

I feel it comes down to the grow setup and tent or closet location and overall air flow. Some times like in summer you just need a little down time to keep the temps good.

Most people go 24 hours on during veg to get the grow done marginally faster.

 

[BrokrnEyes]

What about blue led on 24/7 during bloom though? I agree that I have read a lot about leaving the lights on 24 seven during veg but for when I am getting from this article, since the blue LEDs don't have a red spectrum, it should be safe to leave them on during bloom as well. It kind of sounds like the plant would be essentially working at 50% during the night cycle, so would have say a 40/8 cycle make sense to restore the processes you mentioned or would it just confuse the plant?

 

[Papageno]

I don't use LEDs but I highly doubt leaving on the lights will allow the blooming hormone build up needed to bloom. My understanding is any light zaps that hormone immediately. I don't think the wavelength has anything to do with it as it has nothing to do with photosynthesis.

If you want to get fancy look up the gas lantern technique but I wouldn't waste any time on this.

Don't try to think outside the box until you have a few grows under your belt. There is plenty to screw up without trying to venture down a path not recommended.

If using LEDs then use a veg light 24 hours in veg and a bloom light adder running 12 hours in bloom. There is nothing more to think about. You have a lot more important things to be worried about.

 

[mokel]

I was told by a canna employee during a workshop, that everything, except green light (which is mostly reflected by chlorophyll), that exceeds 3w per m² is going to harm your plant during flowering as not the 12 hrs daylight are necessary for flowering but the darkness

 

[Stanovich420]

Plant will flower under blue leds aswell,but not as good...
In flowering they need MORE red to get job done right.
Regarding leaving blue led on during night cycle,it will definetely make it worse-hermie-stunt-etc

 

[Papageno]

Not to belabor this but I think we are all thinking way too hard here...

What would likely happen is it would never see a night cycle just a 12 hours of poor day cycle, like morning or in the shade. It would never start bloom. The plant would stretch and thin out trying to find good light. It would fill the whole grow space and never have started bloom since there was never a chance to build up the blooming hormone.

Then after one gives up and chops it back to re-start veg you will have wasted a few months. But since you never got it into bloom it wont need to hermi.

 

[BrokrnEyes]

OK thank you for the info guys, definitely glad that I started posting on the forums otherwise I would have gone with my initial thought!