DIY LED Grow Lights

There are a number of problems associated with grow lights

• Expensive to purchase
• Require expensive ballasts
• Expensive to operate
• Short limited life spans
• Hazardous materials
• Fragile
• Excessive heat
• Limited K values

 
After quite a bit of investigation I have come to believe there are two types that stand out

• Ceramic Metal Halide (CMH)
• LED

Neither is cheap to purchase and at this time LED is very expensive, but I just found components to build your own LED light bar which exhibit none of the problems I've listed above!

A Standard LED Grow Light

The components to build and equivalent 400W 36000 lumen grow light at less than 1/2 the cost!

 To build the equivalent grow light would require one PCB and 40 LED Chips at a cost of about $100 plus some labor and a few items like Power supply, solder, wire and box.

This is just one of many LED K values that are available and a wider spectrum could be made by including other K valued LED Chips.

12V power supplies are very inexpensive thanks to the computer industry. 

Total cost about $200

While searching for your components you may find some bulbs are listed in 'mcd' rather than lumens.  Here is a converter calculator to help you design the grow light you wish to build. 


Coming Soon!  New LED technology
http://www.bbc.co.uk/news/technology-22106718

Energy

I began this aquaponics project [Click Here]  with a goal to create an energy efficient system and explore the viability of a commercial system.

On March 8th I added a water heater and have maintained the temperature between 72F - 80F.  My utility bill begins and ends on the 20th of each month, so the heater was added midway through the cycle. 

The tanks are well insulated R11 and the grow room is insulated at R19.  The heater was only required several hours a day.  The weather has been slightly warmer than normal, but many days were near freezing and the glazing is not finished so I have a fair amount of infiltration.

All of these variables detract from an accurate assessment, but it is my conclusion that the cost of maintaining the heat for tropical fish and an ideal grow bed temperature is adding about 120 KWH/month or $34/month during the winter.

Recently my efforts have been to cool rather than heat.  I'm using an evaporative cooling system which consumes about 180KWH/month at a cost of about $50/month. 

My plants were lanky and pale, so on March 18 I added 270W of supplemental lighting, and they have improved.   I have also added one more light for the duck weed bringing the total to about 300W.

I have been running the lights for 18 hours a day which is consuming about 5.4KW/day.  This additional usage pushed me into the next tier and adds an extra 4 cents per Kilo-Watt, but I'll use my average cost of $0.28/KWH for these calculations.  I'd estimate the supplemental lighting adds about 160KWH/month or $45.00/month.  I will reduce this or discontinue supplemental lighting when the long Summer days arrive.

In order to reduce costs  I'll look into solar or propane heating, and I may be able to reduce the hours I supplement light or find a better glazing design.   Currently I have 40 sq ft of South facing vertical glazing in front of 25 sq ft of grow bed.   Direct sunlight is cut short by the winter season as well as the solid insulated walls and ceiling.  

In addition to lighting and temperature control the pump also consumes about 36KWH/month or about $10/month and tank lights at about 16KWH/month or $4.50

Adding this all up I get
$40.00 - Temperature Control
$45.00 - Lights
$10.00 - Pump
$ 4.50  - Tank Lights
$99.50 - Total utility per month.  

I feel the options are:

1. Find a way to direct more light onto the grow bed
2. Build additional grow beds outdoors for use only in the Summer
3. Experiment with less supplemental lighting to find the minimum amount required.
4. Change my crop seasonally and switch to cold water fish.

I am currently running the indoor grow room as well as a pond and have begun construction of an outdoor cold water aquaponic system using IBC's.  I should be able to compare the costs and production in a few months, but it seems obvious to me that the only way to make aquaponics cost effective is to raise fish that are adapted to your climate and plant seasonal crops.

Even without the additional cost of supplemental lighting my costs would still be about $50.00/month.  That is probably a break even point considering the cost of food and other items such as test kits.

I have enjoyed doing this and will continue to look at it as a $1200/year hobby with food as a benefit.

Additional advancement may come from recent technology as found in these links

Solar Grow Tube 

Inteligentry

Lights

The more I learn about this the less I feel I know.  This is a draft and will continue to be edited.

UPDATE: 4 August, 2012
I've taken some flak for using CFL's  with a recommendation from Jon Parr
to use Ceramic Metal Halide (CMH) bulbs.  If I continue to supplement light next Winter I will switch over to CMH.

This is what Jon had to say:

Jon Parr  (LINK) - ."CMH are not necessarily the best, but they are my favorite. MH emit blue light for veg, HPS emit red light for flowering, and CMH emit full white beautiful spectrum, including UV. Photosynthesis uses a fairly narrow spectrum of the blue and the red, and non at all in the green, in fact reflecting it, which is why plants are green. The jury is still out on how exactly UV is used, but side by side comparisons show healthier plants when a little UV is added, IDK. I do know that HPS are cheaper, about $20 and on the shelf at Home D for a 400W, as opposed to $50 for a CMH 400W. Bob, and Kevin, you will be amazed how cool HID lights are compared to flouros. The bulb itself is hot, yes, but the total heat generated per watt is less, and a vertical CMH bulb needs no cooling at all, not even a fan, as the natural convection draws a cooling air current upwards past the bulb. I pay $.45 per KWH, so efficiency is paramount, meaning no reflectors or glass to suck lumens. I hang a vertical bare bulb, and situate my plants around it in zip-grow style towers. Ideally, I don't want a single photon striking anything but plant. Is the UV dangerous from a CMH? Yes, probably, just as dangerous as it is from the sun. I have never noticed any discomfort, but I am in the sun working every day anyway. I've read that sensitive people advise wearing sunglasses, long sleeves, or even sunscreen if working around bare bulbs for extended periods of time. I have them lighting up my whole shop, but they are in closed fixtures with a glass panel, which blocks the UV.

I get my CMH here, and ballasts, and sockets are available for about $15 at your local head shop. http://advancedtechlighting.com/cdmed18.htm For flat grows like Bob and Kevin have, you'll want to add a wing style reflector to bounce light back down to the plants. The linked site also show some pictures of failed bulbs, and how the arc tube remains contained. The Phillips brand they sell are rated for open fixtures, a big plus for bare bulbers like myself."

For an explanation of why CMH are the preferred grow bulb WATCH THIS.  Basically it is because they have a complete spectrum, and last longer

corvet_gxip4297riox@members.ebay.com
worked out a custom auction for me!
15 - 14W 5000K 800 Lumen CFLs
and
15 - 18W 6500K 1170 Lumen CFLs
for $65.00 including shipping charges!

But the auction he has listed now says
30 CFL Bulbs Total 15-2700K 15-6500K so you may have to ask for what you want.
CLICK HERE

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ORIGINAL POST
All along I have spent the time to find the best values when I had to purchase anything for this project.
With lights I feel that I may still be on the learning curve, but here is what I've found.
T5 and CFL seem to be the best bargain when heat, energy, and initial cost are all considered.

The luminous efficacy of a typical CFL is 50–70  lumens per watt (lm/W).
A typical T5 HO (High Output) bulb produces 92.6 lumens per watt.

T5 systems come ready made and have a professional look.

CFLs can be slightly less expensive if you are willing to invest the time to build a light bar.  Here is how I built mine.  It's 16 standard E27 bases connected in parallel on a 1 x 6 board.
As an example two light bars each with 8 - 5000K 800 Lumen and 8 - 6500K 1170 Lumen CFL bulbs should produce about  31,500 Lumen when new, but about 25% loss will occur during the lifetime of the bulbs.
Below are some pictures of how I made it.

I first laid out the pattern and drilled 1-3/8" holes

Then I cut out the opening for the electrical connections to the standard E27 light bases

This is the top where the wire get connected.

This is the result. 

The Kelvin scale measures the “color” of the light.  CFL bulbs come in at least 6 different color spectrums. 2700K, 3000K, 3500K, 4100K, 5000K and 6500K.

http://urbangardenmagazine.com/2010/02/plasma-grow-lights-the-promises-of-full-spectrum-plant-lighting/

 
CLICK HERE for a full explanation of Color Temperature.

Expect to pay more for the higher K value. 
2700K tends toward the red end of the spectrum and is good for fruiting while 5000K and 6500K tend toward the blue end of the spectrum and are best for growth.  I plan to mix a few 2700K in for good measure, but I will use mostly 5000K and 6500K.  Alone you may think a 2700K looks bright and white, but next to a 6500K it will look dim.

The cost difference is significant.  I was able to find 2700K at Costco for less than $2.00.  If the package does not have information about the color spectrum or if it simply says "Full Spectrum" it is most likely a 2700K bulb.

The best price I found for 5000K and 6500K was $4.14 at Lowes.  I looked at eBay, but it appeared that the big box stores have the best deals until corvet_gxip4297riox@members.ebay.com helped me out.

The cost of each white plastic E27 base was $1.34 at Lowes.
Total cost for a 16 light, 368 Watt, 25600 Lumen light bar was 21.50 for the bases, and $66.00 for the lights. Plus a 1x6 and some wire for a total cost of about $100.00.  It took about an hour to assemble.

I found R48 - T5 HO Fluorescent Grow Lights for $145.00 on eBay.
Considering the small difference in price the T5 light may be your best option.  

The value if you buy your bulbs at a Lowes is about 200 lumen per dollar for the CFL 6500K and about 160 Lumen per dollar for the T5, but I think the T5 looks better.  If money is an issue or you require a lot of lights then the cost may be the deciding factor.

For more information about lighting reference these links
http://en.wikipedia.org/wiki/Lux
http://en.wikipedia.org/wiki/Lumen_%28unit%29
http://www.egc.com/useful_info_lighting.php
http://www.littlegreenhouse.com/guide3.shtml
http://www.pcgrowcase.com/cflgrow.htm
http://www.apogeeinstruments.com/conversions/lux-ppf.html
https://www.greenpassion.org/index.php?/topic/25726-lux-versus-lumen-par-versus-ppf/ 

An excerpt from Marijuana growers handbook by ed rosenthal, newest edition sums up the math very well.

Lux is a type of measurement of visible light to the human eye, is an industry standard in Europe.
PAR is a measurement of Quanta of light in PAR range, used in Horticulture research, and the a measurement of "daily light integral" accumulated PAR light during an entire day, also used in Horticulture research.
There are other PAR measurements for Energy in PAR range, and total energy, that is used by engineers and researchers.

PAR is usually expressed in Moles, which measure the number of light photons (one mole = 6.02 x 1023 photons) and are frequently combined with units of area and time to give you moles per meter per day.

Page 101:
Light output or intensity is measured in several different units, including candelas, foot-candles, lumens, lux, and moles. Many of these units are based on each other, and some are more commonly used than others. They measure three basic things:
*the amount of visible light emitted (candelas, lumens)
*The amount of light that reaches a defined area (foot candles, lux)
*and the total number of light particles (moles)


envind added this comment in the forum discussion "Lux Versus Lumen & Par Versus Ppf" on the GreenPassion forum
...
Lumens measure the visible light or "luminous flux" emitted in a defined beam. a single candela light source that radiates equally in all directions produces exactly 4(pi) lumens (12.6); a 23 w compact fluorescent emits about 1600 lumens.
...
The lux is similar to the foot-candle in that it measures the visible light intensity (luminous flux) that reaches a particular area, defined as one lumen per square meter. so 100 lumens concentrated in an area of one square meter equals 100 lux. if that same 100 lumens is spread over a space 10 square meters, you have 10 lux.


 

The gangs all here

Today I added the remaining 22 fish into the 800 gallon aquaponic fish tank.  They were very happy to see their old friends and a good time was had by all.

I built a light fixture today with 16 CFL bulbs in a straight line 8 feet long.   It's a lot of light, but I may need two.

Costco has a good price on 23W 1600 lumen CFLs (about $8.00), but there were some rebates that knocked another $2.00 off the price.  So each box of 4 costs $5.99 right now.    I was going to use T5 bulbs, but I saw that, and did the math.
I'm waiting for a response from the manufacture for more information about the light spectrum.  All I have been able to find so far is that they are "Full Spectrum".  I'm hoping this will work for me, if not Costco will take them back.

I'll post a picture of my finished grow lamp after it's painted, and the specs if I hear back from Feit Electric.

Here are the specs on the CFLs that Devin Duhaime is using very successfully.

Philips 41409-4 - 26 Watt - CFL
100 W Equal - 5000K Full Spectrum - 82 CRI - 114 Lumens per Watt - 15 Month Warranty