DIY TUTORIAL: How to build a 50w full spectrum LED grow light for under $5 bucks!

11 months ago

diy LED 1.jpg

In this post I will be doing a quick step by step tutorial teaching anyone who is interested how to build a 50w LED grow light for around $10.00. If you can source a few donor items it is possible to build one for even less, around $5.00!!! I will leave all the links for the bits and pieces needed at the end of the tutorial.

Let's Get Started!

diy led 2.jpg

To build a light you will need a handful of items and some basic skills. Nothing serious, if you can rewire a plug you are golden :-)

So as you can see in the above picture we have a few items....

  • 50w COB Full Spectrum LED
  • Thermal Silicone Cement
  • CPU Heatsink ( I find them lying around save a buck if you can)
  • Solder and Soldering Iron
  • Power Cord and Plug

A handful of items we can turn in green gold:-)

diy LED step 3.jpg

First make sure the contact surface of your heatsink is clean, I use rubbing alcohol or sandpaper to clean the surface. This is essential to make a good bond between the chip and heatsink.

Once your heatsink is ready, simply take your Thermal Silcone Cement and spread a thin layer over the contact point of the LED chip like in the picture above. It's important to use Thermal Silicone Cement because this actually bonds the chip to the heatsink, simple and done!

Note: They can be pulled off and replaced if needed.

diy led 5.jpg

Next simply center the chip and stick it down.

It really is that simple! Try not to push on the orange bit in the center when placing the LED chip, this bit contains the diodes and if you press on it you might damage one. Once in place the Silcone Cement will be dry enough in about 30 min to work with again.

Tip: When cementing your chip in place, press down over the 4 mounting holes and work it into place a little to ensure a good bond.

dit led 6.jpg

Now for the fun part! Next you will need to solder your power cord and plug to the LED chip. The nice thing about these chips is that they have a in-build on-board driver. This allows the chip to be connected directly to either 120v or 220v AC.

Please note: Working with AC current is very dangerous. If you are not familiar with electricy please ask for help. I am sure you will find a helper to solder the Live and Neutral wires for ya. :-) Remeber blue is Nutral and brown is Live. This is easy to identify with the L and N specified on the chip.

After soldering dont forget to insulate the exposed soldering. I recomend a blob of either silicone or apoxy to cover the contact points and prevent a nasty shock in future.

And that's it, plug your light in and you are ready to go!

You might have noticed I am not using a cooling fan. When using a chunky heatsink like the one above, it is not required to have a cooling fan when running just one 50w LED chip in a open grow room. However if needed a simple pc fan will work perfectly.

Alternately a oscillating fan in the grow area simply blowing on the light will also work fine. These LED chips have heat protection sensors that will turn the LED off if it get's to hot protecting it.


If you would like to use the exact COB LED and Thermal Cement I used in this tutorial please click on the links below.

As for the CPU heatsink and power cord I am sure these can be sourced by most people locally. In all my years of building lights I only bought heatsinks when building custom lights for people. Otherwise they easy to come by and save a buck at the same time. :-)

Also I would like to note I have been buying from this specific LED supplier now for a few years and never had one hassel. There LED's are GOOD i use them all the time!

Thanks for stopping by I hope you enjoyed this tutorial. I am giving away all my secret's here lol! Thanks for the support and as always I am looking forward to all comments and questions. Also if you need help please drop a comment, I will be more than happy to facilitate were possible.

Peace, @bitminter

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Wow who would have thought it could be so cheap! This is a great tutorial that will help people get started growing, Well done!


Thank you @blunt-smith much appreciated.

Thanks! Super useful tutorial!

Also, love the smoke banner in your tent! I'm totally doing that!


I printed that banner the day I joined smoke, its a bit worn out now but I love it!

These are just the kind of tutorials I love around here! Filed for reference when it's time to try this out ...


If you ever need help with anything drop a comment in one of my posts and I will get back to you as soon as I can. Cheerz


Nice one!

What a treasure, and with your great promise of more secrets to come! I love the DIY approach to life, by-passing the packaged and ready-made.

When I'm able to grow again, I'm sure I will have learnt a lot from your posts. Resmoking for reference.

Thank you very much for sharing this! 🔆


@barge thank you very much happy to help!

Great tutorial.. I will def build some of these once I eventually move to a bigger place. :D


It's a great little project that is fun and a affordable way to expand your grow. I have come to realise that the COB chips are now a tried and tested concept and can be cheaply manufactured. 99% of all the Chips are made in China so the prices some of the retailors charge for brand name grow lights that run the same chips is madness.

44% OFF!

The next couple days as well. Thank you again for this information, I just picked up a couple for some tests I wanted to do for myself. :)


Awesome that is a great deal I should grab a fewfor myself aswell. Pleeease keep us posted I amvery curious to see what you think. Following cheerz :-)


My LED's arrived today, and then later today I ordered more.

I found a different thermal adhesive than the one on aliexpress, and the reviews are really good. :) IF it's as good as the aliexpress brand, the price is much better for 10 grams. :)
Brenner Conductive Silicone Adhesive


Awesome thank you very very much for the link looks great! Have fun with your new toys you gonna bang out some serious lumens with 570 watts! I have also recently ordered a few and I have also found something so will do a update soon.



lol :D
Looking forward to seeing what you deliver. :D

What a gret tutorial even for layman, thanks.
I always had fear of playing with the electricity, so I don't even know if I'd had a courage to even try it.


If you know of anyone who is handy or has experience with soldering they will be able to help you no problem. If you want DIY lights build let me know I will put them together for ya and ship them out!


That's so kind of you, but I'd say it is too much hassle and if I ever decide to grow, I'd go with only one or two plans, for my needs.


One light will be enough then for a small plant or two. It would be my pleasure to send you one if it helps. I have recently made a order for quite a few chips, dont worry I got them very cheap. Soon we will figure out how to contact each other without compromise to our smoke accounts. Then I will post you one to try out. Then all you do is pay shipping and its yours!

Trust me you doing me a favour, It's my dream to one day grow medical cannabis legally on a comercial scale. I have the entire business plan and everything lol. So if you decided you want one ,your feedback would be priceless!

This is the prototype I would like to send you. It's a 50w full spectrum chip, 12v power suppy and fan all in one. As you can see the prototype is very basic, however I am saving for a 3D printer so I can finish things off. Then I plan on hitting the market at killer prices, around $20 each with a 1 year guarentee.

This little light puts out around 5000 lumen and runs super cool. After running for hours you will be able to pic the light up without burning.

Quite informative, it would be really helpful guide for me when I plan to grow at my own house :)

With 💕,


Happy you found it useful :-)

Awesome :) Good job explaining. :D


Thanm you!

Very good and helpfull tutorial. Now its time to order the LEDs to build my own lamp. Thank you!


Glad it helped you! Please let me know if you need any help or have questions I am happy to help!

Question, what distances did you use between a single 50w cob and your plants? My first time using full spectrum led and I'm not finding details on this particular light. :D