Custom LED light

Hey guys. My job as an electronics assembler lets me buy LEDs and LED drivers very cheaply, So I'd like to build my own custom LED.

I've done a ton of research into LEDs and my science background gives me a good grasp of wavelengths and PAR.

I'm planning 2 different lights. One is for a small cloning chamber. It is going to be the ceiling for a 2x2x2 box. It will be complemented by 2 small t8 grow lights on each side, so getting every wavelength perfect is not as important for this one. I'm putting 16 3.3 watt LEDs on a 2x2 foot area, it will come out to a little under 50 watts of light, plus 25 watts of t8 grow bulbs.

My questions are these: Will this be enough light for a seedling/cloning chamber? What colors/wavelengths should I be getting? For simplicities sake, I'm thinking of going with 8 reds and 8 blues, as the t8's will fill in the rest hopefully, if not then 8 reds, 4 blues, and 4 cool/warm whites.


The second light I'm going to be building will be the strongest flowering LED I can build, with some UVB LEDs as well as a low power and high power mode. Ratio of LEDs for this/color spectrums? This one needs to be a full spectrum light.

I recommend led strips; but hey if you want results you can wire hundreds of leds; but that sucks. Ok for seedling chamber.

Plants like blue and red light; blue is most efficient where 445-465nm blue I think is 95% efficiency; red, is like 75% at like 660nm range

White leds unlike MH/BULBS/ECT. tend to peak to create a peaky wave in the blue and red areas. a 6500K white will have a blue peak at 3000000/6500K=461nm average= blue peak around 450nm and a a red peak much smaller around 655~

While the 3000000/4500k white led=avg 665; with a big red peak around 675nm

Bulbs don't produce big peaks and have a lot of wasteful yellow/green light.

I found it hard to find an ideal blue or red that produced a lot of lumen s with low watts. However I found a very efficient sets of 4500k 6500k whites that have blue and red peaks with little green and yellow light; and peaking at the most efficient light NM absorption ranges.

For cloning and veg stage you want to focus more on blue light than red. If anything go 10 blue 6 red... or something along those lines.

If you really want to get fancy you could do 9 blue, 5 red, 1 UV, 1 IR....

What purpose would the IR serve? I've heard that the UV would help flowering plants, but IR would just dry the plants out faster, wouldn't it?

How would a mix of 1 red, 1 blue, 1 cool white and 1 warm watt and 1 uv do for the ratio? Seems like that would be the easiest. How much UV is necessary for the3 benifits?

I disagree with the more blue than red. I can only advice you to read http://www.gardenscure.com/420/lighting/117772-how-build-your-diy-led-array.html
They also talk about spectrum needed. And they came to the spectrum 3 Red 1 deep blue 1 Cool white/neutral white. Also the red LED's should be 50/50 625nm and 660nm (red and deep red)
I do feel that I trust KNNA more than any seller of LED lights. His words are wisdom!

EDIT: Also IR is not really needed, the white LED's do give out some IR. and IR light is just heat and I've seen no real documentation stating that this is needed.

19 blue, then 6 red then put 4.5 magenta and another 4.5 abused asshole color orange/red then your good

IR is not necessarily needed, but when used not in excess it helps to promote healthy blooming. Too much IR can damage plants but if not oversaturated it can be beneficial. There are many studies that examine the effects of IR on plant growth. Some say it can increase the bloom rate, makes the flowers more dense, and keep photosynthesis active longer at the end of the light cycle for up to two extra hours. Il have to go bank tonight and try to find some links.

There are a variety of spectrum's that work well as we can see from various brands of LED panels. Some swear green does nothing, some have green LED's, etc. etc. There's a million different variations, the only real static thing we see with any consistency is that vegging models have more blue than red, and flowering models have more red than blue.

LED lights designed for both veg and flowering usually still favor red spectrum's over blue, and IR and UV diodes are included on lots of lights designed for both the veg and flowering cycles.

Could you get me a link of a model that uses IR LEDS in it's design? It's thermal radiation, I can't imagine the plants would benefit from that. Maybe the far reds...

Thanatos99 said:

Could you get me a link of a model that uses IR LEDS in it's design? It's thermal radiation, I can't imagine the plants would benefit from that. Maybe the far reds...

Click to expand...

There are a ton of LED's that use 720-760nm... that's IR....lol

Anything over 700nm is IR.

From Hydro Grow LED;

--Uses (126) 3W Super High Output LED's
--200W approximate power consumption
--6 High Quality 1.5W Cooling Fans (9W total)
--Intense 60 Degree Lens
--Coverage Area: 18" x 30" @ 12" above your canopy
--Full Spectrum: 440nm, 470nm, 525nm, 640nm, 660nm, 740nm
--Spectra Ratios: 75% Red, 10% Blue, 15% Green
--6 foot long power cord available in 110V, 220V and International Plugs
--Dimensions: 19" x 12.5" x 3.5"
--Weight: 17lbs

From FERO;

Full spectrum: 660nm, 640nm, 585nm, 460nm, 730nm, and 430nm.

From HTG;

WIDER SPECTRUM - The 7 BAND LED UFO has SEVEN LIGHT SPECTRUMS to help your plants grow to their full potential! 660nm Deep Red for Chlorophyll A, 630nm Bright Red for Chlorophyll B, 460nm Bright Blue for Chlorophyll B, 430nm Deep Blue for Chlorophyll A, 10,000 Kelvin White/Blue spectrum to fill out a complete light spectrum needed for plants to grow properly, 390 nm UV Light and 850nm InfraRed (IR) Spectrum for VIGOR and Mold/Mildew Prevention

You didn't know the majority of companies use IR and UV?

While you want to have the majority of the light used for photosynthesis, light in other spectrum's has other beneficial affects on the plants. The sun provides an incredibly large range of spectrum's and the closer we can get to simulating all of the suns beneficial light, the better the plants will be.

It seems like there's been such a focus on hitting the peaks for photosynthesis a lot of companies forgot about the other light required to make great bud. Now we're seeing more companies using Green, IR, and UV....

People are using UVB reptile lights for plants too.... seems to be working.

I probably came off confusing earlier; I did a lot of research on LEDS and the light spectrum. The leds I looked at were blue/red/uv and white.
The white leds produced the highest amount of lumens per watt.
when looking for the right white leds hue in kelvin I also looked up the datasheet on the LED that had a graph representing the output. The great thing was high peaks in blue and red with very little yellow green light; Which means the plant was using more of the light being created; especially compared to bulbs.

The Percentages I gave in the earlier post; were relative to the plants ability to perform photosynthesis; this is the scale I based some info on.

View attachment 1893225

I got the peaks mixed up in the previous post; but the info is still relative.

I recommend white

ihatefoxnews said:

I probably came off confusing earlier; I did a lot of research on LEDS and the light spectrum. The leds I looked at were blue/red/uv and white.
The white leds produced the highest amount of lumens per watt.
when looking for the right white leds hue in kelvin I also looked up the datasheet on the LED that had a graph representing the output. The great thing was high peaks in blue and red with very little yellow green light; Which means the plant was using more of the light being created; especially compared to bulbs.

The Percentages I gave in the earlier post; were relative to the plants ability to perform photosynthesis; this is the scale I based some info on.

View attachment 1893225

I got the peaks mixed up in the previous post; but the info is still relative.

I recommend white

335SMD leds or 3528SMD leds.​

Click to expand...

I'm not trying to be rude, but you need to keep doing a bit more research...

Lux doesn't mean anything to plants. Lux is how much light is visible to the human eye and the peak of lumen sensitivity is at 555 nm (green), a color useless to plants. Whereas PAR is the measurement of light between 400-700nm which is the specific spectrum where active photosynthesis occurs.

White LED's are "brighter" because they produce more green light, the light our eyes are most sensitive to. 2700k and 6500k temperature bulbs have a substantial amount of light focused in the red and blue spectrum's respectively but still produce green and yellow light, which is less effective for photosynthesis. So, a white LED can produce substantially more visible light while still producing less PAR than an LED producing light of a specific colour.

once again the datasheets for these leds produce most of the light in the blue and red hues. the mixture creates the hue in K of the light which 3000000 divided by K to convert to NM.

So a 6500K is avg HUE of the wavelength 3000000/6500=461nm Now, that doesn't mean 461nm only, that would be a blue with maybe a green hue. in reality that LED produces a wave that looks like this.

the particular sheet I used I would estimate an avg of around 480nm or 6200k light honestly I have no idea. I would use something more blue, the leds I found had a lower red peak, much less yellow green light and a similar or wider blue peak.


So obviously you will have greens and yellows in most white lights and if you measure lumens with a device the reacts the way a human eye sees green light brighter then it will only appear lighter without helping the plants. Yes I get that; yes I learned that; yes I don't need you to tell me. As you can see this particular led provides a broad range of light that wasn't measure in a PAR? format. Lumens and MCD were prevalent. Neither do these have a PPFD measurement; but they still work and would be difficult comparing to your avg grow light. The main difference I've noticed is lots of grow lights used the most efficient wavelengths and produce virtually no white light. However these white leds in the numbers if measured vs a led grow light; price per performance will outperform bulbs and perform very close to a grow light; if the price wasn't as a bargain as I got.

compared to a metal halide the spectrum of this aforementioned white led is much more efficient.