DIY led panel for microgrow

rokko1337

Member
Hi, what do you think about this led color ratio?

740nm - 4
660nm - 20
640nm - 10
610-615nm - 4
470nm - 4
455nm - 2
430nm - 4
380nm - 2

RED:BLUE:IR:UV

34 : 10 : 4 : 2

setup - growtent Homebox mini 30x30x60 (cm), 50x2W led.

Also, some people suggested to replace 610-615nm with WW and 470nm with CW. I think that, replacing of 610-615nm is a good idea, but not for 470nm (maybe it's better to replace 455nm?).

http://pics.simhost.org/images/677483051a463fd6a32a.jpg - light spectrums
http://pics.simhost.org/images/817780951a463fe4eda6.jpg - light temperatures

P.S. I cannot understand what wavelength is better, 470 or 455.

Setup #2:

740nm - 4
660nm - 20
640nm - 10
WW - 4
CW - 2
455nm - 4
430nm - 4
380nm - 2


RED:BLUE:WW:CW:IR:UV
30 : 8 : 4 : 2 : 4 : 2
 

turnip brain

Active Member
Thanks, part way there...

is a scan of something on paper in a magazine or something. Wondering what the original source is and whether it is considered accurate today.
 

SupraSPL

Well-Known Member
If it helps your decision, there are a few wavelengths that are readily available in top bins and cheaply. Very hard to beat those and when it comes down to it cannabis loves photons. As far as I know there are no UV or infrared LEDs that can get anywhere near the efficiency of these listed below. Same goes for cyan, green, amber and orange.

450nm Luxeon ES M4R bin
630nm Cree XPE P3 bin
660nm Luxeon ES EX6 bin
660nm Oslon SSL 3T bin
3000K Cree XTE R3 bin

Good luck!
 

rokko1337

Member
How about Emerson effect (IR + 660nm) and resin production with mold protection (UV)?

Also I saw nice responses about this light http://www.truliteled.com/ they have only 2 red, 2 blue and 1 IR bands.
And I don't know about 470nm wavelength, because of not everyone use it.

some another info:
https://growblu.com/blog/first-published-led-grow-light-test-part-1/
http://www.ledgrowlightsdiy.com/led-grow-lights-for-cannabis-grow-guide-spectrum-wavelength.html


740 nm - 4
660 nm - 20
640 nm - 10
warm white(2700 K) - 4
470 nm - 4
450 nm - 4
430 nm - 4

RED:BLUE:WW:IR
30 : 12 : 4 : 4
 

SupraSPL

Well-Known Member
You can get 450nm blue that is 55% efficient (700mA 50c). My foggy memory of UVA LEDs tells me they are lucky to reach 15% efficiency. On top of that, cannabis has no problem with resin production without UV wavelengths. HPS bud:

DSC06203a 10.jpg

The same goes for infrared. Any smalls gains that might be made by the emerson effect would be outshined by the huge difference in efficiency between reds LEDs and infrared. The Cree XPE P3 is 42% efficient (700mA 50c) and the Oslon Hyper Red 3T is 42% efficient. Off the top of my head, the best infrared LEDs (that are actually available on the market) are lucky to reach 20%.

Based on that I am skeptical of the value of UV and infrared LEDs. From my experience LED buds do have more frosting and more terpenes than HPS buds, but I believe that is due to the 450nm deep blue and the decrease in infrared. I think the HPS infrared cooks some of the flavor out of the bud and I suspect the plant "thinks" it is getting bombarded by UV because of the presence of the blue.

The green side of this bud was in the "shade, the purple side was exposed to the LED with plenty of output in the 450nm range:

DSC06693a O18c anthocyanin.jpg
 

rokko1337

Member
Ok, than how about ratio listed in my previous post and diodes with 470, 430 nm wavelength and their ratio 1:1:1?

Also what do you think about table from this article?
P.S. I believe, that using small amount of IR diodes (8-10% of red spectrum diodes) gives more benefits in growth than all-red diodes (40:4 > 44)

P.S.S What can you tell about wattage of diodes for small distance from buds (grow tent height 60 cm (~ 2 ft)? Can 2/3W diodes bleach them in distance 5-7 cm?
 

SupraSPL

Well-Known Member
I have great respect for those willing to spend their time and money on testing. That said, a panel assembled with generic chinese LEDs will be hopeless compared to a panel assembled using the LEDs I mentioned above. They are very lucky if they are working with LEDs in the 10-15% efficiency range. It would be much cheaper to use fluorescent light (15-25% efficient), or even better, big HPS (35-40% efficient).

They claim "we are constantly testing different spectrums that will improve a plants fruit yield." Assuming they are using the most efficient emitters currently available, adding UV and IR will have the opposite effect of their stated goal. On the other hand, if their research can guide the development of new growing LEDs from top notch manufacturers then they may be on to something.

Regarding the table, I would need more background knowledge in order to know whether there is actually anything there of value. One thing that is for certain and has been empirically tested, top shelf med grade weed can be grown without UVA UVB or infrared. Since there currently no efficient sources of those wavelengths, building a lamp using them will be more of a sacrifice in the name of science :)

If my memory is working today, Stardustsailor posted some positive info regarding cyan 470nm LEDs. My take on it is that they are nowhere near the efficiency of 450nm so I automatically discount their value if you are building a lamp today. If down the road they catch up in efficiency I will definitely give them a shot.
 

jcmjrt

Well-Known Member
P.S.S What can you tell about wattage of diodes for small distance from buds (grow tent height 60 cm (~ 2 ft)? Can 2/3W diodes bleach them in distance 5-7 cm?
Yes. You might get away with being that close with 1 watters or really low current drive on 3 watters...I don't really know as I haven't used those but 5 - 7 cm height above the canopy with 3 watters driven somewhat normally can lead to damage to the plant.

Fluorescent lighting - including T5HO which can grow some very nice buds - can be kept very close...in fact needs to be kept close.
 

rokko1337

Member
Finally I'll try this setup:

660 nm - 22
640 nm - 10
warm white(2700 K) - 4
470 nm - 4
450 nm - 4
430 nm - 4


RED:BLUE:WW
32 : 12 : 4

3W diodes powered as 2W.
 

rokko1337

Member
I could not find the right diodes, so this is most close setup:
730 nm - 8 (1W paired)
660 nm - 20 (2W)
625 nm - 10 (2W)
warm white(2700 K) - 4 (2W)
cold white(6500 K) - 2 (2W)
440-450 nm - 5 (2W)
410-420 nm - 10 (1W paired)
 
Top