Quote Originally Posted by ledtime
Weezard,

I have been following your posts for quite sometime now. I am simply fascinated by LED grow light technology. You've had some time to play, and I have a manufacturer who will let me truly play with the array and let me put in whatever LED's I wish. I am however limited to the 1W LED's.

I'm sure you've seen all of the chinese manufactured lights. I've seen the lights from this manufacturer tested and these LED's DO put out at the advertised wavelengths. :thumbsup:

The market is currently flooded with "Tri-Band" lights of course meaning they are putting in orange with the red and blue. Is the orange worth it?:wtf:

In my humble opinion, no.
Should do as well or mo' betta adding the same number of 660nm. leds.
I think the tri-band lights are based on a false assumption.
Somebody looked at relative bud quality 'tween HPS and low-power led grow.
They thought, as I did, what does the HPS have that the leds do not have?
Most obvious is that large spike of yellow/amber energy.
I did a side by side test. 625nm. vs. 660 nm.
Then I did a blended light test with both wavelengths.
All 660 outshines the blend.

So, back to thinking mode.
HPS comes up slow and fades out slow. So there is a spectral shift towards IR as it cools off.

Hmmm.
In the wild, we have a shift to red as the blue light scatters in the evening. After sundown we still have incoming energy in far red and infra red.
That's why I'm playing with the 730nm. at lights out.
I've read all about the phytochrome conversion and 730:660 role in it's conversion.
Phytochrome is clearly not the whole story here, just another clue.
But, I think the application of 730 nm. is key.

(We also get some 730 nm. in the morning pre-sunrise. Yet another avenue of interest)

This manufacturer has the capability to put 735nm LED's into the array for me.

I doubt that adding some 730nm, leds to the mix and turning them on and off with the same timer as the rest will be very useful.
But, kicking them in 10 minutes before lights-out and running them for 20 minutes after, just might be, I intend to find out.
If not? we all learned something.


What I don't know is how many of each type of LED to put in the array. I'm tinkering with their 119 LED array. I figured you would know what the optimal wavelengths were as DH's light is hauling ass with his grow from the pictures I saw in another thread. :rastabanna:

That's not all about the light, yah?
Hermie's got a :greenthumb:.

How would you suggest I break up that 119 light option? Majority 660nm,

Yes

a little 640nm?

Not so much.

Some 462nm?

Wouldn't hurt.

and then some 735nm?

See above.

Again the question is in what ratio?

If you are stuck with a fixed ratio array there will be compromises.
The R:B ratio will depend on your goals.
Got limited headroom? More blue.
Last few weeks of budding? More red.
4:1 seems to be a good "in-between" ratio.
My large array runs all-ahead-full at 5:1.
I can adjust the red downwards to play with the ratio.
Still fiddling with that.
Got more hints than conclusions.

The next exploration will be a variable ratio vs. time.
5:1 in the morning and evening with a slow ramp to bring the blue up for a 3.5:1 at noon then have it fade back to 5:1 in the evening. A little burst of 730 nm. at the "off n onnie" transitions and I'm hoping we can outdo HPS for half the cost in power,

I'm also getting an all blue UFO for veg. What nm LED should I use for that?

Not sure that monochrome a good idea.
Plants can and do convert wavelengths to something that chlorophyl can use.
But, TANSTAAFL.
I have never tried growing with a single color, so I won't say it can't be done well.
It just does not seem right to me, so I'll let other folks experiment with that.
That said, I'd shoot for a mix of the 2 blue peaks in the absorbtion curve.

The pricing is unbeatable for my test models.

Hmm, 'bout $135 ?

I can even get him to make me just and all 735nm light bulb in place of the party light. But again, I'm not sure how many LED's would be needed to match the output of the party bulb.

Nor am I. Seems to be a toggle with a "tipping point"
Still :weedpoke:.

Any light you can shine on this
A man after my own heart.
would be greatly appreciated. I truly respect the fact that you build all of your stuff on a budget and it blows away lights that people spend thousands of dollars on. And you sense of humor is great....I've had many laughs from your posts!
Just had a good chuckle from yours, thanks.

More important you nudged the on switch to me "thinker".
(Just toss me a concept and I'll amuse myself for months.)

I expect we'll be learning choke from your efforts.
Welcome aboard m8!

Regards,
Weezard