Introduction: LEDsGrow
MY FIRST PUBLISHED PROJECT.
Every constructive comment, good or bad, is appreciated.
Here is my example of a basic GROW PANEL with LED strips.
Feel free to modify the details as you go along. (Bigger, more LED's, ...)
The LED strips are sold in 5m rolls for €10 or less.
Power supply can be bought for €20 or less.
All the other stuff needed, I already had or got for free.
- Wood plank.
- Aluminium tape.
- 2-wire cable, 0,75mm² audio cable works fine.
- Connectors.
- 4x screw hook.
- Chain. (Plastic would be great, metals works too.)
- Electric tape. (White would be best, others work too.)
Equipment:
- Drill.
- Solder iron & tin.
- Sharp knife.
- Tool to cut chain.
Step 1: Choosing the LED's.
In short:
Plants mostly require far red 660nm and blue 440nm lighting.
White light, like summer daylight, is needed during the first stages of growth.
While at the later flowering phase, far red light becomes more important. As it resembles the coming of cold weather.
So, a white light for a young plant and a far red light for a maturing plant.
LED strips have some great advantages:
- Waterproof, if needed.
- Less soldering then individual LED's
- 12Volt DC, already in serie/parallel assembly.
- Easily upgradable by added strips.
What's needed exactly?
- cold white LED strip, 12Vdc, waterproof.
- grow LED strip*, also 12Vdc, waterproof.
*grow LED strip contain multiple far red LED's for each blue one. For example, 4red/1blue.
** I bought my LED-strips at AliExpress
Step 2: Panel & Reflection.
The very basic solution is to cut the desired dimensions out of a fairly rigid but light material.
After that, cover the bottom side with aluminium tape.
You could add a down facing edge. Slightly improving light efficienty.
Step 3: LED Lay-out & Installation.
Note: LED strips are cut on specific places. (for example, every 3 LED's)
As explained before, I made a small white square shape and a bigger oval shape of coloured LED's.
During the lay-out I kept a clearance of twice the width of the strips.
This way I can easily double the capacity and still have 1:2 width of clearance.
Use the knife to cut away the clear plastic on top of the solder points.
I also did NOT YET glue the solder ends. After soldering, we'll put some tape underneath for isolation.
My panel will only serve a small plant.
So I'm going for a bare minimum of lights and add some strips only if needed.
Next, drill a whole near the solder end of each strip.
... The cable goes through,
... solder solder*,
... tape between solder-point and panel,
... tape covering the solder point.
* The coloured strips need your +wire on the +12v point and your -wire connects the 3 remaining points, together.
Step 4: Completing the Circuit(s)
Although the pictures say otherwise, it's all pretty easy.
To combine the strips, just connect all +'s together and all -'s together. (parallel circuit)
I did this twice, creating 2 channels/ 3options:
- ALL WHITE + 1 REDnBLUE
- ALL WHITE + ALL REDnBLUE
- Only REDnBLUE
The connectors are very basic. But I already had them and free is always nice.
You could use just one connector and add a switch between the first and second channel.
I didn't bother because that switch will only be used every few weeks.
Step 5: Power Supply
The most important part here is to GO FOR MORE.
In the .pdf you can check the precise calculation.
First I calculated the needed power for each "uncut piece" of LED strip. (each 3LED's)
After that, just sum up the "uncut pieces" and multiply by power for each piece.
In my case, it's only around 26Watts.
But, I may need to double in the future. So that would make 52Watts.
FOR SAFETY, only use a power supply for 90% capacity.
So I'll need a minimum power supply of 60Watts. (12Volt DC @ 5A)
Check: 60Watts -10% = 54Watts ( > 52Watts needed)
I bought a power supply unit at TME
A very fast but more expensive retailer, compared to AliExpress
Attachments
Step 6: Almost There...
Last stop: How to hang the panel.
I used 4hooks coming together with 2chains.
This way it's cheap and easy to adjust the height.
Because these LED strips barely heat up, the lamp can be very close to the plant without burning it.
Now the experiment can start: Growing with the bare minimum of electricity.
In this micro-garden I'll also add a 140mm 12Vdc computer fan and an air purifier to suck in fresh air.
This totals to LESS THAN 70watts.
Even if the lights need to be doubled, it'll still be less than 100Watts.
Fingers crossed for the results....

Participated in the
Make It Glow! Contest
15 Comments
7 years ago
Don't you have problems with the heat those ledstrips produce? Led may be much more efficient then ordinary lamps but they still produce a lot of heat. I had a similar setup with all white leds and it almost melted. I switched to an aluminium plate with some heatsinks on the other side, and now the temperature is managable (~ 50 C)
Reply 7 years ago
As mentioned above I LED a lamp out of 24"X7" glass shelf with 30Watts of LED light strips. it is only warm to the touch. NO heat sinks or metal or fans are needed to cool it. The key is that the strips don't produce all the heat in one spot. Roughly 70% of the glass is covered by led light strips. This means each square inch of glass is getting about 0.17 watts of heat which can easily be transferred to the air without special metal heat sinks or fans.
Reply 7 years ago
See my reply to ThinkTinker, I use far more power. BTW, I have mixed red, blue and white leds.
Reply 7 years ago
Well they did warm up, but less then I expected.
(The room does have a slow but constant ventilation)
The panel is around 40°C at the end of it's day.
The metallic tape itself is also working as a heat sink.
Even with my seedling at 5inches (12cm), there are no signs of burns.
(These LED's have a very wide beam-angle so don't place too far away)
Reply 7 years ago
Yes, that metallic tape probably is a good idea. I went for an aluminium plate with wooden strips around it and a thin wooden plate on top. In the plate on top I have installed two slow rotating fans (less sound) and the heat is duckted away. But then again I use far more power (approx 100W) and the whole setup is only slightly larger than yours is. Without the fans the temp would quickly rise above 60 Celsius (then I start burning my hands)
7 years ago
One note is that while many plants do well under red and blue light, some don't. I made a red and blue LED lamp for my orchids but at 30 watts it didn't help my orchids that much during the dark months of winter. I replaced that with 30Watts of mostly white and got much better growth.
The spectrum you posted shows that chlorophyll absorbs light best a red and blue wavelengths. But studies half shown that the small amount of yellow and green light the plants do absorb is used chemically for growth. Additionally i read about a green house that was made with panels that filtered out the green and yellow light and only allowed red and blue to reach the plants. Scientist monitored the pant growth and found some varieties of lettus didn't do will while most other food plants did.
From what I have read and my own experience a mix of white and red and blue is probably best and some plants may need a lot more white.
7 years ago
families=them voice rec not as good in noisy environment?
7 years ago
I am going to follow your suggestion to make families not for plants but just for internal lighting thanks
7 years ago
you will burn your electronics out faster by not having enough power than by having too much
7 years ago
there is a big debate online as to how plant growing LED lights need to be 1W each minimum. i see lots of people using these strips. if you are growing plants that don't need much light these will work great. but if you had a tomato plant or other sun seeking farming plants, you may want to consider upgrading to high power leds. you can make a cheaper and stronger custom light
https://www.instructables.com/id/LED-lights-1/
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above setup will work great with all seedlings however, assuming we bring the plants close to the light and lower them as they get bigger. the problem with these lights is not the spectrum but how far will they travel..
7 years ago
Very simple solution. I´m going to do something similar. Can you tell me, what kind of strips you have used?
Thanks.
Reply 7 years ago
I used 12Vdc LED strips marked as "grow LED strips" (only red & blue)
The white strip is an ordinary "cold white LED strip"
The links will take you to AliExpress, but mind the long delivery-time.
Good growing!
7 years ago
This would be great for an indoor garden or vertical farm! I might actually build this!
7 years ago
I like it. I think it would be great for side lighting. Try a par force bat wing for the top ;)
7 years ago
Very cool project. Thanks for sharing.