Status
Introduction
We don't have a lot of rooom to garden outside. And wouldn't you know it, we don't get much sun in the house. I built this grow light to use on a 4 plant hydroponic garden I built. My test subject for this light will be herbs.
Overview
The colors we are interested in for our light are red and blue. Different LED lights you can buy have differnet ratios of these two colors. There are excellent articles on the internet describing how plants use these two colors. Now if you want to view your plant's natural beauty then this is not the light for you.
For this light I used red and blue LEDs. I used 3 red LEDs for every Blue LED. Hopefully this provides some good results.
Specifications
I built the light on perf board. See the pictures for the layout. The light draws 10.7 watts of power and runs on 12V. 1.5W is dissipated in the resisters. I used 136 LEDs and 34 100 ohm resisters.
Construction
Please use the pictures as a guide for construction. Each row contains a 100 ohm resister and four LEDs in series.
Greatly dimmed so you can see the LED colors
Top view of Light
Bottom view of light
How Much Light Do You Need?
This is prob the biggest question. Depending on what you are growing you'll need from 5W to 15W per square foot. Lettus and herbs will need 5W to 10W per square foot. And vegetables will need 10W to 15W per square foot. What you are aiming for is 25% to 50% of the watts per square foot used by a HID light. For example if you use a 200W HID light you would only need a 50W LED light.
What Can I Grow?
The ratio of red to blue is important to plant growth. This light has a high percentage of blue light. This makes it well suited for non flowing plants such as herbs.
Conclusion
This is an extremely bright light. It should provide enough light for a small garden. By small I mean 1 ft by 1 ft.
Comments
Matt? — 07 May 2011, 19:22
Iwas trying to find out if Icould get plans for led grow panel 300w. if not what next best one I could get.
I would like more info. I like looking at your light,but not building one. But thank you its hard geting any good info. on led lighting
Hi, please post exact parts list including cross references, a schematic in 54 different formats, and step-by-step idiot-proof instructions in 22 languages. Please provide sources for the parts along with current single-piece pricing. Also please include any future updates to this project that you haven't thought of yet. By posting them ahead of when you have thought of them, it will save all of us idiots much time. Thanks in advance.
Hi, great work. I'd like to do something like you. I have a question - what kind of LED did you use? Are these High lux flow LEDs? how much candela ? thx a lot..bye
I admire your innovation. However LEDs need to dissipate the heat they generate or they will burn out prematurely. If you look at commercially available units, they all incorporate heat sinks.
You would also be very happy with the results of using multiple spectrums of red and blue respectively. Especially for fruiting.
I don't believe in selling snake oil. Or giving it away for that matter. This information is here to show that its not just companies selling the "perfect light source" for growing plants indoors. I like this light but it didn't give me what I think I'm looking for.
I'm building other lights to test and compare with this one. When I'm happy then the rest of you will be happy. I don't want to lead people a stray building something that isn't going to perform well.
There is no doubt that LED lights make great light sources for indoor gardening. The question I'm trying to answer is "How much LED produced light is needed to get the same results as other light sources?"
i read in this thing that led loose ligh after 2-3 months. you have to have the SHITTYEST leds EVER if the run out that soon. most leds last from 6 to 10 years(thats why comercial modles are so expensive) and you can grow flowering plants like cannabis with them as long as you supplement you led with some hid.
i grow indoor coca that i aquired on a trip to south america it gives my coffee the buzz i need to get me threw the day grown under 3 ten watt lights
With a chosen name of Ganjarooster, it isn't surprising they know of no legitimate use for grow lights !
At this point I don't have formal plans for this light. This is one of many prototypes I'm working with. Once I decide on which light I like I'll create plans for people to use
rcamp? — 05 January 2009, 07:58
Well you don't realize that a lot of gardeners start their seeds indoors under lights. The backyard gardener who wants to get a jump start on the season will use grow lights.
Will this light work for Marijuana? Cause there's really no legitimate use for grow lights in the private sector.
iv? — 07 October 2008, 11:21
Nice..so a 100w led light system should be equivalent to a 400w HID system?
You should post how to make a 100w LED system..with resistor information and what not..
very nice, I would like some info on how to wire the LED's.
What would be the RED/Blue Color Ratio for a Tasmanian Poppy?
rcamp? — 20 February 2008, 13:46
When I chose the leds I looked at wavelength vs brightness vs cost vs availability. Given all the choices I chose what was cheap and easy to buy. If I find a cheap source for 650nm leds vs the 625nm ones then I'll switch. The blue leds are very close so I don't see a need to change them.
rcamp? — 20 February 2008, 13:38
At this point I won't be sending out info. This light for me was a prototype that I'm no longer using. I have a new much brighter light I've been testing. When finished I'll have forsale a blank circuit board. I will also provide information on where to buy the LEDs.
— 05 February 2008, 10:39
how to avoid intensity loses after 3 months
i am afraid that the intensity of leds will decline after 2 to 3 months
rcamp? — 10 December 2007, 07:50
Visit http://www.gardeningcamp.com and you'll see the pictures of what I'm growing. Currently I'm growing basil. Next I'm going to grow california white sage.
I should correct myself, many do use hydroponics to grow herbs... but many more who grow other types
herbs ey?? What kind of herbs would that be...?
I don't know too many who use a hydroponic system to grow herbs... unless...
Ryan? — 10 November 2007, 22:42
Agree with others... please post the schematics and also a weekly photo / notes of your progress.
I will mention your work on my site, urbancommune.org
I've been looking into doing this for awhile now, and upon seeing this I must say well done it looks nice. Just a quick question, did you take to time to look up specific light frequencies or just go with any red/blue LEDs. I googled photosynthesis light absorption and found a very neat graph relating it to frequency.
thank you
rilo? — 01 August 2007, 23:03
great job on the light . I would like to try and buid my own light as well.
Can you give me a list of possible suppliers that you used to make your light and about how much did it cost?
TIA
I've had to reduce the wattage of this light to 7.5 watts. To get the full 10 watts you'll have to seal the botom part of the light in epoxy.
My goal is 5 watts per square foot. I really like your numbers. None of the standard light meter give me the measurements I'm looking for. Since the testing equipment for measuring the light intensity at different wavelengths is very expensive I'm resorting to just growing plants and taking notes. I'll update as testing continues.
Interesting! But with the high efficiency of leds shouldnt this be good for more area. Like 6 of your units in a 4x8 area,32sq.ft. After all HID or HPS is mostly heat
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have fun!
