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RED / BLUE ratios for led grow lights

PostPosted: Mon Dec 30, 2013 10:48 am
by krister

I have mailed the person behind this site , and asked about the subject

so i think as there was a forum on this site , i'll give it a try here as well.

I would like to have your opinion about the never ending question about the red / blue ratios for growlights

I have just finished my diy growlight containing ..
30w 450nm - 40w 660nm - 30w 630nm

calculated at blue 1,15w and reds 0.8w at 350ma

I am mainly into growing hot peppers like habaneros and hotter species,

but also stevia , you now , the sugar substitute plant from south america.
(only green leaves, no fuit = only blue light??)

If i read from US forums , than everybody seems to think that the red band is the most important when growing hot peppers , with benefits of everything from sturdier stems, thicker leaves , to more fruit

But , if i read native (im from sweden) websites and forums than most people tend to use blue and white led , or cold white cfl, lights,

and red bands of led are considered as useless in this spheres

weird , aint it?

So , your opinion about red / blue ratios for both hot peppers and stevia
would be highly appreciated

I can run my light in only red , or only blue, and i can run each color in half power, and of course both colors att full power at same time

I cannot separate 660 from 630nm

ok thanks,

krister sweden

Re: RED / BLUE ratios for led grow lights

PostPosted: Mon Dec 30, 2013 2:21 pm
by SisterMaryElephant
Welcome to the forums!

Unfortunately, this isn't really a DIY type forum but plants do need the red spectrum (and others) too. I couldn't tell you what the right ratio should be for the plants you want to grow but since you have already built a light, you might as well try it and see how it works.

Pepper plants can get pretty tall so I'd suggest using the more powerful 5w diodes for better light penetration and tying them down or pruning if they get too tall.


Re: RED / BLUE ratios for led grow lights

PostPosted: Tue Dec 31, 2013 4:50 pm
by krister
Is there not at least any kind of rule of thumb where you should start from ..kind of "basic ratio" where from you start elaborating from?

This is my first chili growing ever , so my highest priority is to have peppers to summer , getting my light "tuned in" is secondary interest

Re: RED / BLUE ratios for led grow lights

PostPosted: Tue Dec 31, 2013 5:00 pm
by SisterMaryElephant
I doubt there is a "rule of thumb" for that but, as I said, this isn't really a DIY type forum so I can't be positive.

You can look at the specs for different LED grow lights and try to figure it out but I'd imagine that there are wide variances. People here have successfully grown peppers with the CLW LED lights but I don't even know the ratio for those lights either.

Re: RED / BLUE ratios for led grow lights

PostPosted: Wed Jan 01, 2014 4:07 am
by krister
Yes, as you say , they all have different specs. that what makes it so hard to figure out,

But ok... If i would try out different ratios with my plants , how long would i have to run a specific ratio to be sure that the result is coming from the present ratio, (how quick do plants respond to a change in light?) one week ? two weeks ?

Im a bit worried that i would read the result wrong if plants have a delay in reaction , so when i think that "this week that plant grow exceptionally well" , it is actually caused by the light that the plants got the week before !

Re: RED / BLUE ratios for led grow lights

PostPosted: Thu Jan 02, 2014 12:20 am
by SisterMaryElephant
They all have different specs because there is no "rule" regarding spectra. ;)

You'd have to run several full plant cycles, preferably side by side, in order to compare. There are no shortcuts short of copying a known successful light's ratios.