Picture of 108W LED Grow Light Panel
This is my first instructable, I hope you all enjoy it and hopefully some of you will get some use out of it.

Growing with LED lights

Using LED lights for plant growth is a nice alternative to using HPS and metal halide. While many argue that the results are simply not the same in recent years LED's are slowly gaining respect in the indoor plant growing community.

+Uses up to 80% less energy on your bill making it a green solution.
+Lower heat and easier to control temperature.
+Long life span up to 50,000 hours
+Precise spectrum for photosynthesis

The main disadvantage with LEDS is the cost of certain high end units. This instructable is here to give those that are interested in plant growth with LED's a nice cheap alternative DIY solution.
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Step 1: Tools and Materials

Picture of Tools and Materials
+Soldering Iron
+Wire stripper
+A little series/parallel wiring knowledge

+Cooling fans($6-$20 or salvage)
+Thermal glue ($7)
+Nuts + Bolts ($3)
+2 - 3 feet of 18 AWG wire (3$)
+Metal Panel 7"x7" from ($16)
+Led Drivers x 3 (36$)
****use bulk rate because you get a disscount when purchasing 3 or more****
+DC transformer 8-14V (salvage)
+AC power cord/plug (salvage)
Total: $110-120

LED's from Ebay(about 40$):
3W Blue x4  (455nm)
3W Blue x4  (445nm)
3W Deep red x16 (660nm)
3W Red x12 (630nm)
***you dont have to use the same configuration as me, try your own let me know how it works out for you***

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forex5x9 months ago

Would it be possible to use a power supply from a recycled computer to drive the LED's?

WayneO2 forex5x12 days ago
I'm sorry, but with 18 leds and only a 12 V power supply, the leds would be in 6 stings of 3 leds in series (approx 10V) each set of 3 leds in series would need a 2.2 ohm resistor also in series. the six strings, with their resistors, would all be connected in parallel... the only catch would be that each string needs 900 mA and there are 6 strings... that's 5.4 amps and you have only 5 Amp power supplies...

the resistors are necessary to allow the strings to evenly share current, else the string with the lowest combined forward voltage would "hog" the bulk of the current and the rest would be "starved".

The resistors would also need to be 1 watt each.

The ideal drive would be a single string of 18 leds driven by a constant current power supply set to 900 mA (this would require a total string voltage of 59.4 V)
WayneO2 forex5x23 days ago

Yes, this can be accomplished, but you will have to add the appropriate Constant-Current regulator(s) to insure that the LED's are not over-driven.

Do you know how to make it work 18x 3W Red (630nm) in serie with 18x 3W Blue (445nm) on a 12v dc 5amp power supply? (i got two 12v dc 5amp power supply)

GoonyLex (author)  forex5x9 months ago

yes it is possible, however you will require an additional circuit to control and maintain a constant current.

How to make it work 18x 3W Red (630nm) in serie with 18x 3W Blue (445nm) on a 12v dc 5amp power supply? (i got two 12v dc 5amp power supply)

micgreen1 month ago

waow, the hotline still here since 1 or 2 years? Bravo ! (i'm french, sorry for my english). A little first question for you goonylex : is it possible to put drivers out the panel (for heatless, moistureless and practicable)? Like a ruban wire and mollex connector(s) one meter lenght ? Must i have bigger section of wire between (molex) leds and drivers ? Thanks a lot.

oups, mistaking : this little question is't only for the author but for the experts too ! Sorry mr. Watergunz and Adrian...

John L1 month ago

I have a question that I have not seen asked yet. Per your instructions you used two types of Red and two types of Blue LEDs. Why is this imperative? Why can't I use the Warm White(2700k-3400k), and Cool Daylight White(5600K-7000K)? It seems to me that this would be a better overall way to go, since its really combined frequencies in order to produce the white light.

Watergunz2 months ago
Just got done making this Instructable, amazing!

I must say heat is an issue here from the LED's not the drivers, please use a cooling system to lower the temperature for sure!
GoonyLex (author)  Watergunz1 month ago

Good Job! looks good :) happy growing

axmejo1 month ago

Hi. One array of leds pulsates att about 3hz. And another barely makes the LEDS glow. I have the mentioned drivers from and 3W leds from eBay going from 2.2V to 3.2V I'm perplexed by this. Anything give a clue?

GoonyLex (author)  axmejo1 month ago

with no load what are you measuring coming out of the drivers?

axmejo GoonyLex1 month ago

Hi all three drivers push out between 59~61 V dc

GoonyLex (author)  axmejo1 month ago

that is strange then, try measuring the resistance between each individual led to see if you find any resistance variation that might point you to a bad led. If that does not work send me a link to what you purchased.

Fitchett2 months ago

If you hook up the LEDs (per driver) in parallel instead of series:
1.) Would it still work?
2.) If one LED went out, would the rest of them on that driver continue to work?

gofasteddie5 months ago

Are you powering 12 leds with each power supply?

Yes he is powering 12 LED's with each driver.
GoonyLex (author)  gofasteddie5 months ago

Yes each driver supports 9-12 Leds.

jjosef864 months ago

how close can the leds be? i want to put 150 3W leds on a panel. what size panel would be ideal?

AdrianL2 jjosef863 months ago

as long as you have a place where the driver can breathe and stay cool, you can place them very close together. All depends on your boards of course

AdrianL23 months ago

I know there are many critiques here in regards to price and other nit picks, but all in all, you did a great job in making a basic DIY LED grow light that will work. I made mine a little more "sophisticated" using qty100 1w LEDs. I configured it in array that would evenly distribute the UV and IR evenly. My choice of color and qty are as follows:

54% Red 660nm, 20%Red 630nm, 16%Blue 470nm, and 10%Blue 425nm, all with 60 degree beam angles.

I keep it about 14"-18" away from the top of my plant, and I did add mylar around the perimeter so light would bounce everywhere. So far, my plants have not complained one bit about being confined to a closet.

I may just bump up my next one using 3w LEDs and get a ton more usable light, but for now, my plants and I are content. Keep up the good work!

gofasteddie5 months ago

Very nice DIY and easy to follow.

I'd like to build a larger,just more leds,but same basic system.

If one LED fails will the other LEDs powered on that circuit fail to light?

GoonyLex (author)  gofasteddie5 months ago

Unfortunately yes, if one led fails all 12 will stop working. But because the drivers support 9-12 led's simply make a + to - jumper ON THE BURNT OUT LED , and the remaining 11 will work. Do not go below 9 leds. Also leds have long life so shouldn't be an issue.

Is this also the reason for having 3 seperate circuits and drivers instead of one large circuit/driver? Fault tolerance and easier time finding the failed LED?

I was thinking the same thing, you may be right
The Freak3 months ago

Nice build! Maybe you could also use some lenses on these LEDs, which I'm planning to do when I'll build a growlight. These LEDs have a beam angle of about 120 to 140 degrees, so you waste quite some light there. They are sold specificly for these LEDs on ebay for not a lot of money and available starting from 5 degrees.

astearon7 months ago

Can you please give me an estimate on 2 things about this build ?

I need to know the total power consumption (kw/h or whatever) of this system and also what is the effective surface area it can light ? I mean how many plants can i cram under there ? :)

GoonyLex (author)  astearon5 months ago

Sorry your question is a bit hard to answer as plants come in all shapes and sizes. As to your power question its power consumption would be 0.108 kw/h.

ninjatails2 years ago
How did you get your metal panel for $16? The quote they gave me was $47...
Found it:
GoonyLex (author)  ninjatails2 years ago
i just went to the store and thats the quote the guy gave me. You need about 1/4" thickl plate or more

Thank you for clarifying how thick the aluminum needs to be. I'm excited to try this.

I did find better pricing for the aluminum. The 1/4" is half the price, and even 1/2 inch is less than what you've shown

shipping is additional, but that's true from either source for me

thegodswan8 months ago

Hi Lex. Very nice instructable, truly motivating. I am ready to go but safety is very important to me, so I was just wondering if you could help me on how to add the famous fuse to the circuit to make it more safe. Thanks again.

x1c09 months ago

Firstly, thanks for the instructable! I was looking into pre-fab units and my diy spirit was tugging me to refrain and further my research. you helped pull together info i had not yet gotten to with led lighting. I will be adding into the system a set of 600 nms too as it seems this could be useful for carotenoid development.

I have been looking for salvaged aluminum to mount the lighting but may have to go with purchasing a new plate. You mention a thermal fuse that could be added to the system. How is that done? do I wire it in to the wires of the driver before going to the wall cable or to the latter? or do i attach these prior to the driver?

Since these are for seed starts for my roof top garden, I was thinking about pushing more 440-455 nms. Any success with that?

GoonyLex (author)  x1c08 months ago

Hi , your welcome and I'm glad it is of use to you.
Il take a picture this week to demonstrate how to add a thermal fuse. Typically it is added into the circuit , I like to add mine in-between the LED's themselves. The fuses I added have to be in contact with the plate but not directly because the case of the fuse is a terminal (so you have to be careful not to create a short).

lfilek9 months ago

Hello there GoonyLex, So I found all the pieces I think:


730-740 nm ( DC forward voltage :1.7-2.4Vdc : Forward current: 700MA) x 2

620-630 nm (voltage 2.3-2.8 current 700MA) x 8

440-445 nm (voltage 3.0-3.4 current 700MA) x 5

465-470 nm (voltage 3.0-3.4 current 700MA) x 5

520-530 nm (voltage 3.5-3.8 current 700MA) x 2

650-660 nm (voltage 2.2-2.4 current 700MA) x 14

total of 36 LED all separated into 3 rows of 12

LED Driver 36w (constant current 700MA, output voltage DC 36-41V Input voltage 220Vac/230Vac/240Vac.)

I know I have to reach the minimum voltage on the driver for it to work, I have a question about mixing the different voltage on the led for example 660 nm has 2.2-2.4 and 440 nm has a voltage of 3.0-3.4 .

I would love to get your opinion before I order anything since I dont have any experiance with electronics

lfilek lfilek9 months ago

the link to the driver didnt post right, but this is the one

and another driver I was looking at is a bit cheaper and I might go with that one

LexLuger lfilek9 months ago


Im happy to hear your working on making this panel :).
Well you said you are using 36 LED's, do you have 3 separate drivers?

LexLuger LexLuger9 months ago

Also I don't think mixing them will be an issue, its not the most refined method but it should not give you any trouble, if it does msg me and well get to the buttom of it.

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