CFL Light Tutorial

[Roseman]

Allow me to share some information with you about Lights, especially CFLs.
(Compact Flourscent Lights)
This will include HOW MUCH LIGHT DO I NEED?



CFLs vs HID Lights

If you want to start an argument fast, then visit an Internet Grow Forum or Chat Room and mention CFLs vs HID Lights. (HID Lights = High Intensity Discharge Lights)
Let me just tell you a fact. HID Lights (High Intensity Discharge Lights) are much more efficient than CFLs (Compact Fluorescent Lights) and they grow FASTER and penetrate a large plant much better than CFLs do. HID lights grow tighter denser buds too. That is a fact no one should argue. HIDs win easily.

Wait a minute. What costs more to purchase? What requires a fancier Reflector and costs more to hang? What cost more to use and adds more to the electric bill? What cost more to handle the HEAT? What do I have to VENT? What will VENTING cost?

HEAT? VENTING? I can touch a 200 watt CFL for ten seconds and not burn my hand. I can hold a burning 42, 65, or 85 watt bulb in my hand for five seconds and not get burnt. I can touch a HID bulb for half a second and have a serious blister and burn. Touching a HID bulb is like touching the burner on an electric stove. If you use HID bulbs, not only will you have to cool the bulb, you will have to cool the grow area too. Growing with HID lights requires VENTING the HEAT, and that cost extra money, BIG MONEY.

If you are a large scale grower, or commercial grower, HID lights are best for you.
If you are a small grower, a closet or tent grower, an occasional grower, a small scale personal use grower, then CFLs are your best, easiest, cheapest way to grow.

As I mentioned, I like the cheaper CFLs because of their mobility and ease of use. When I did my first grow over three years ago, a 65 watt CFL bulb was the largest made and sold. Today I see up to 300 watt CFLS, but I do not advise using the larger watt CFL bulbs.



Let me share a magazine article with you about Lighting.

From Ed Rosenthal:

In the new Skunk Magazine there was a question in the "Ask Ed" section that just made my night last night when reading it...



The Question Was:

I intend to grow a single cannabis plant in a space 1' x 2'. What light would you recommend? I was think of using four 30-watt compact fluorescent lamps. Will this be enough? Cost isn't an issue but I am deterred from getting a high pressure sodium [light] because of the amount of heat the bulb produces.

The Answer Is:

As you mentioned, you have several lighting systems to choose from, including compact fluorescents and high pressure sodium (HPS) lamps. Among HPS lamps you have a choice between a single 100-watt lamp which uses a total of about 120-watts and emits about 8,800 lumens(73 lumens per watt) or a 150-watt lamp, which uses about 180 watts and emits almost double that-15,800 lumens (87 lumens per watt).

A 42-watt compact fluorescent (CFL) emits about 2700 lumens(64 lumens per watt). Four 42 watt CFLs use 168 watts and emit 10,800 lumens. Other size CFLs have a similar efficiency.

However, that is only part of the story. Plants use mostly red and blue light. Yellow and green light is of little use to them, so light that is emitted in these spectrums is wasted energy. Most of the light emitted by HPS lamps is in the yellow spectrum. Only a small amount of the emitted light is in the orange or red spectrums, which plants use efficiently. Warm white fluorescents (2700 Kelvin) emit a greater portion in the red and orange sectors.
Although fluorescents produce only about 75% of the light per watt that the HPS does, the amount of light usable by the plant is equal or probably higher with the fluorescents. You may wish to experiment to see if adding a single cool white CFL to replace one warm white results in shorter, stouter stems and more vigorous growth. The reasoning is that warm whites don't emit much blue light, which the plants use for photosynthesis and to regulate their growth. The cool white bulb supplies the blue light.

My call for your unit would be to use several (three to five) CFLs with a total input of between 120-160 watts. Although the 150 watt HPS is a bit more efficient that the CFLs in total output, watt for watt the fluorescents provide as much useful light as the HPS lamp. Heat is another consideration. The HPS runs much hotter and emits more heat than the flourescents.

Make sure to use reflective material around the garden so that any light escaping the garden is reflected back to the plants. Any light that doesn't get to the plant leaves is wasted.


Look at a lumen/watt ration of various CFL's. The higher the wattage of CFLs, the lower the lumen/watt ratio. This chart was submitted by Jerry Garcia, a grow buddy from another grow site, and edited for typos.

For example...

the 200w listed at 9250 lumens for a lumens/watt ratio of 9250/200=46.25

the 150w is listed at 7500 lumens for a l/w ratio of 7500/150=50

the 125w is listed at 6500 lumens for a l/w ratio of 6500/125=52

the 42w are listed for 2700 lumens, l/w ratio of 2700/42=64.28

I have some 26w that give off 1700 lumens for a l/w ratio of 1700/26=65.38

GE lists some 13w that give off 825 lumens for a l/w ratio of 825/13=63.46

So, according to these numbers the most efficient bulbs for growing are the 26w that emit 1700 lumens. If you used 8 26w bulbs (208 watts total) you'd be getting 13,600 lumens...4,350 more lumens than a single 200 watt CFL. AND the eight 26 watt bulbs would cost less than the one 200 watt bulb.

I suppose you need to purchase more sockets and cords and things to support 8 bulbs, but in the long run more lower watt CFLs seem like the way to go.

 

[Roseman]

I love the Reflector Clamps for my CFLS and I am not fond of the larger reflectors that hold 2 or 3 bulbs and are suspended from two chains.
The 3 bulb reflectors have their purpose, and in some instances they are perfect or ideal. You can duplicate the sun's rays of 10,000 lumens with three 105 watt bulbs in a good reflector. But I like the ease of being able to hang, move and re-arrange my lights, and Clamp Reflectors work best for me for that reason. Another reason is I rotate the lights around often. And as fast as my plants grow, I have to adjust (raise) the lights everyday. Let's look at some CFLs.



This is a SPIRAL CFL BULB.

42 Watt Bulbs average $ 9 to $10.00 each

65 Watt Bulbs $19.99 average price ($16.95 now at Lowes and Home Depot)

85 Watt Bulbs average $29.00 each, can be found for $24.95 on the Internet

*********************************

This is a Tube Type bulb, not a Spiral bulb.

105 watt bulbs average $34.95 to $38.99 each. 105 watt bulbs come in Tube type and Spiral. Note Tube Types do not work well in Clamp Reflectors and an Extension Socket will be needed.




Note: To use a large CFL bulb of 105 watts in a Clamp Reflector, you should and have to use an Extender like this, to get it to properly work and to get a good connection.

 

[Roseman]

What are my options?

CFLs come in 15, 26, 42, 65, 68, 85 and 105 watts and recently last year, even larger 200, 250 and 300 wattages.
The 26s and smaller are not as efficient to me. The 15 watt bulbs are a major waste in my opinion.
26s to 85s do not put out any noticable heat unless you use dozens of them. The 105s do put out some heat, but not as much as HID lights.
I can touch and hold a burning 65 or 85 watt bulb.
The 42's are about $9 to $10 each.
65 watts are abut $17 to $20 each, 85s are $30 each, 105s are $39 to $42 each, average is $40+ each for 105s.
A CFL needs a reflector, like a hood. I like the $12 Heavy Duty Clamp reflectors at Lowes, or Home Depot. Walmart sells a cheaper $8 reflector but it is smaller and flimsey and does not last. The plastic breaks easily.


DUAL SPECTRUM
With CFLs, you need the DUAL SPECTRUM, red and blue spectrums. That does not refer to the color of the bulb that you see. It refers to the kind of rays, like UVA or UVB, or the color temp of the bulb, called kelvins.
CFLS come in 2700 kevins, 3000, 4100, 5100, and 6500.
Low Kelvin bulbs, like the 2700k is for BLOOM OR FLOWERING, 6500k is for the VEG Spectrum. The others are "MID" spectrums or in between.
IF you use the MID-range bulbs (4100) then also use the 6500 and 2700s for a balanced spectrum.
In outdoors, the sun produces different rays in the spring (VEG Rays called Blue) and late summer rays for the Bloom spectrum, the RED spectrum. The sun also produces green, and orange rays, but plants do not use them.

CFLs are fairly new on the grow-scene, in 2006 the biggest made was 65 watts. When we talk about CFL watts, we are talking about the actually electricity used, NOT the equivalent . For example, a 15 watt CFL bulb puts out 60 watts equvalent .

Spiral and Tube type CLFS emit LIGHT FROM THE SIDES, NOT THE ENDS OR TIPS. Spirals do project light in a circle more than the tube type.

YOU CAN GET SPIRAL CFLS (15, 26, 42, 65, 85) AND TUBE TYPE CFLS (105, 250, 300).

How much light is needed for growing?
Depends on the size of plant you are trying to grow. I'll try to answer this "in general" instead of being specific to one size plant. Light seen and perceived with the human eye is measured in Lumens. There is an ideal amount of lumens for growing and a minimum amount of required lumens. The very minimum amount of light required for smaller sized plants grown is around 3000 lumens per square foot. Let me put emphasis on "minimum amount" of light. However, that's not 100% exactly accurate, since although you may have a 10,000 lumen light, the amount of light that reaches the plant varies with the distance between the light and plants, and the reflectivity of the grow area. The ideal amount is somewhere around 7000-10,000 lumens per square foot for average sized plants. As long as the plants do not show burn, as much light can be used as you want to use. (Note, the sun produces about 10,000 lumens per square foot, on a sunny mid summer day).
Contracy to "talk" you CAN have too much light.)

Determining lumens for your grow area:
First determine the square footage of your area (example in a 4 foot by 4 foot area, there is 16 square feet, 2 by 2 feet is 4 Sq ft. ) If you have a 1000 Watt High Pressure Sodium Light Bulb, that produces approximately 107,000 lumens. Divide this by 16 (your square footage) 107,000 divided by 16 = 6687 lumens per square foot. So just divide the total amount of Lumens, by the total amount of square feet, and that's your lumens per square foot.



Note on HIDs contributed by PurpDaddy:
When given the choice of only one light, most marijuana growers will choose an HPS, High Pressure Sodium grow light over MH, Metal Halide, because HPS lights are more efficient (larger harvest).
You can't use a standard high pressure sodium bulb in a metal halide fixture, but you can use a metal halide bulb in a high pressure sodium fixture of the same wattage.
There are special hps bulbs that can be used in a mh fixture and vice-versa. But these conversion bulbs cost about double the price of a standard bulb.
With HID Lights:
A 250 watt fixture will supply enough light to cover a 2.5 foot by 2.5 foot grow area. (6 plants or less)
A 400 watt fixture will supply enough light to cover a 4 foot by 4 foot grow area. (12 plants or less)
A 600 watt fixture will supply enough light to cover a 5 foot by 5 foot grow area. (18 plants or less)
A 1000 watt fixture will supply enough light to cover a 6.5 foot by 6.5 foot grow area. (30 plants or less)

How far away from my plants do the lights go?
The lights in your grow room should be as close as possible to the plants without burning them. There is no such thing as too much light, unless there is overly sufficient heat to dry out and burn the leaves. A good rule with HIDs is to put your hand under the light, if its too hot for your hand, chances are that the plants will be too hot too, so move the light up until your hand feels more comfortable. For seedlings or sprouts, I keep them a little further away from the light, because they are very susceptible to burning and drying out, at these young stages. Placed too far away, and you will get undesired STRETCHING. (defined later)

I can safely place my 42, 65 and 85 watt bulbs one and a half inches near the plant.
I put the 105 and 200 watt bulbs three to four inches near.

How do I decide which lights to use?
Efficiency is very important when choosing a type of light. The wattage is not the most important thing, different types of light produce different amounts of lumens per watt. For example, a 300 watt incandescent will produce about 5100 lumens. (not that you can grow with incandescent bulbs) While a 300 watt Metal Halide (just an example, they do not come in 300 watts), will produce 27,000 lumens. Obviously far more efficient for growing, while still using the same amount of electricity.
Can you afford to VENT the HEAT out of the grow area and cool the area? (HID)
Are you on a budget? (CFL)

Approximate estimated light production:
Incandescents: 17 lumens/watt
Mercury vapor: 45-50 lumens/watt
Fluorescents: 60-70 lumens/watt
Metal halide: 90 lumens/watt
High pressure sodium: 107 lumens/watt


Incandescent lights: Incandescent bulbs are the most popular type of lights in the world. They may come advertised as incandescent, tungsten, quartz, halogen, or simply standard. The important thing about incandescent bulbs when it come to growing is simply this: they suck. Using incandescent bulbs to grow plants is like trying to flag down the Space Challenger with a burnt out match! You can do it, but it won't work. There are some incandescents which are sold as "grow lights." They usually have a blue coating and usually come in 60W and 120W sizes. While they may seem like a good choice to new growers, they are next to useless; they produce some light at a usable spectrum, but only have about a 5% efficiency and generate more heat than usable light. Most of us have these in our homes right now. Don't use them for growing, instead opt for a Compact Fluorescent, CFL, as a cheaper but more efficient alternative.

Fluorescent lights: Fluorescents are far more useful than incandescents. They are efficient enough, and much less expensive than HID (High Intensity Discharge) lights. Compact fluorescent tubes, (commonly called CFLs) are popular with growers because of their good output to size ratio. Compared to standard 4 foot tubes, CFLs are smaller, more easily moved, and more can fit into a given small area. CFLs are good for small grows on a tight budget, and for novice growers, since they do not require any special sort of wiring or understanding of the necessary bulbs for a given fixture, and the small wattage ones (23, 42 and 65) are very widely available. Fluorescent lights come in many different Kelvin (spectrum or color) ratings; often the spectrums are labeled on packaging as being 'cool white' or 'warm white.' Cool white is more of the blue spectrum, and is good for the vegetative stages of growth. The bulbs are ultra white. Warm white light is more reddish in spectrum, and is best for the flowering stage. The bulbs are almost cream colored.

Color rating - Measured in Kelvin (K). The higher the number, the more bluish the light. 4000K-7000K is mostly on the blue side of the spectrum for Vegging or GROWING, while 3000K and under goes from a white spectrum, to a redder spectrum and is best for BLOOMING or FLOWERING.
There is NOT one CFL bulb for both spectrums, two different kelvin bulbs are needed.

One of many mistakes I have made over the years with growing is I wish I had labeled or dated my bulbs. I highly urge everyone to date-label your bulbs. A flourscent bulb can still light up and show LIGHT, but be worn out and not be putting out HALF the lumens it did, when it was new.

 

[Roseman]

Lets look at some Clamp Reflectors:

These are cheap flimsey Clamp Reflectors, average about $9 each. They are plastic and not very durable. The clamps are cheap and flimsey too.

These are much better, stronger Clamp Reflectors, about $ 13 each. They will last forever.

IF you see PLASTIC on the Clamp Reflector, they are cheap and flimsey and you should avoid them.

 

[Roseman]

I have come to believe that two 42 watt bulbs, in one Clamp Reflector is the most efficient, cost effective way to provide light to your Grow.

You need one of these EXTENDERS to go into the socket first:

And then one of these are screwed into that EXTENDER:

To make this:

AND
I saw these in the store:

 

[Roseman]

The Importance Of Mixed Lighting (Dual Spectrum with CFLs)

It is common knowledge that plants absorb warm and cool spectrum of light throughout its life. But I find that the importance of mixed lighting is understressed throughout the growing community.
During the flowering phase of a plants life, Warm light is better utilized to increase the size of a plant's buds. As CFL growers we tend to pile up on 2700k bulbs to increase our yield. In most cases, growers assume that warm light not only grants us larger buds, but insures that those buds are of connoisseur quality as well. This is not to say that one can not achieve a very successful crop off of pure warm spectrum 2700k lighting. We see it all the time as members of the Grow Forum Internet community. But as CFL growers, almost all of us demand a higher efficiency for our dollar.
So what does this mean? Clearly I'm trying to emphasize the necessity of cool lighting during the flowering phase of a plants life. But why? Well thats simple. As many of you may have heard or read before, Cool lighting (6500k) introduces a UVB spectrum that benefits the potency of the buds our plants are producing.
" The writer's own experience allow for a more specific conclusion: If the UVB photon is missing from the light stream(a), or the intensity as expressed in µW/cm2 falls below a certain level(b), the phytochemical process will not be completely energized with only UVA photons which are more penetrating but less energetic, and the harvested resin spheres will have mostly precursor compounds and not fully realized THC(c).

Now it would be completely unreasonable to ask a grower using a 1000watt HPS to switch out for MH lighting even though it produces quality of the weed. Sticking with blue spectrum lighting in a plants flowering phase would greatly decrease the size of the buds and the yield of the plant. People using high wattage systems tend to grow for cash crop. No single person really needs a pound of buds.
" "Metal halide produce the best potent buds with less lumens for the money but better smoke. After years of testing with some friends who did want to keep THEIR recipe (more hps) I found their buds to be harsh, full of CBD, make me eat and sleep. The blue spectrum will give you a final product that have everything included:taste without curing, potency and yield.
For lower wattage growers who grow for self use, and are not on a low budget, it would be beneficial to replace their HPS with an MH for the last week or two of budding. This is because the last weeks of a plants life before harvesting is dedicated to the ripening of the buds, and not the growth of the bud itself. It would not greatly impact the yield of the plant, but have a great effect on the quality. Interesting, but this only applies to a few amount of growers that fit this category.
As CFL growers, we would be fools to ignore such information. It is astonishing that so many fantastic growers to not utilize cool lighting even to a small supplemental degree. We owe it to our selves to scrounge up a few bucks in change and take a drive to Home Depot. Buy a pack of 6500k bulbs (26watts tend to be popular, 42s are better) and set them somewhere not far off from your buds. Don't let your hard work return with unsatisfaction. Added quality with increased quantity(more light). Mixed lighting should be standard knowledge, not found in the advanced cultivation section.

Side Note: Reptile lighting found at pet stores is not ideal for UVB lighting. Yes they do emit a high % of UVB than regular CFLs but they output less light and emit over 12x more UVA light than UVB light which can harm your plant.

 

[Roseman]

And you can put these

in a Surge Protector

and make these:

I fastened the Surge Protector to the log, so I could stand them up in the floor between the plants.

 

[Roseman]

You can easily see how this was assembled.
I screwed a bulb in the bottom of the socket, and put the plug-ins on the sides.

Plug In:

Socket:

 

[Roseman]

All of the 26, 42, 65, 85 and 105 watt bulbs I have discussed here have regular sized sockets and the bulbs fit into any normal socket.
200 watt CFLs and larger have a much larger socket, called a mogul socket.

8' Power Cord with Mogul Socket

If you use a 200 watt CFL bulb or larger, you will need a Mogul Socket.


This is a Mogul To Standard Bulb Adapter

I can not find the words to accurately describe those Parabolic Reflectors, except to say they are AWESOME! The MYLAR does not reflect nearly as much light as a Parabolic Reflector, and I've never seen any reflector that compares. They just fit the base of a 105 or 200 watt CFL.
They are huge and yet lighter in weight than any reflector I have ever seen.
Here you see one with a Mogul Socket and cord:

 

[Roseman]

 

[Stakkur]

Looks nice, now if spiral bulbs were only sold here. I haven't seen a single one in local stores.

 

[OldMedUser]

Awesome thread Roseman!

As I'm going to build a veg room next to the room I have I plan on using a combination of 4' fluorescents and CFLs for lighting chores in there. Chamber for clones, one for mother(s) and room for a couple of bubbler tubs. Going to have to punch a few 6" holes in existing walls for ventilation.

For lower wattage growers who grow for self use, and are not on a low budget, it would be beneficial to replace their HPS with an MH for the last week or two of budding. This is because the last weeks of a plants life before harvesting is dedicated to the ripening of the buds, and not the growth of the bud itself. It would not greatly impact the yield of the plant, but have a great effect on the quality.

About this part. I did have my 400W MH added to my 2-400W HPS for a few days but figured adding it late in flowering might push the plant into thinking it was summer again and inhibit flowering. It was getting too warm in the grow room too with 3-400W lights. Time to upgrade my ventilation system.

So do you think maybe I should change to

A) 1000W MH for the end of days here

B) 1-400W HPS + 1-400W MH

C) 2-400W HPS (current set-up)

D) 1-400W MH + 1-400W EYE Hortilux running in HPS ballast.

E) 2-1000W MH + 2-400W HPS + 1-400W MH + 2-150W HPS and an assortment of 4' florescents and a half dozen 23W CFLs. ;0)

Probably get up in the morning to a house full of pot smoke and a serious if not fatal case of the munchies if I pick option E. lol

for the great info! Rep if I could. 5 stars at least.

C'ya.

 

[Roseman]

LabRat, I can't advise you, I just don't know! I can answer questions all day long about CFLs, but not HID lights. I will ask a few Deep Water Culture to come over and give a response.
Mostly Crazy, PurpDaddy and JonnyBtreed knows, but I don't.

 

[MostlyCrazy]

I think that in the last two weeks of flower it really doesn't matter so much on the lighting you provide. I say this because at that point the N in the tank is at a low level and the plants are just not going to regrow during that last couple of weeks with that res set-up. What I do add are some 6500k cfl's to provide the balanced light that I think is more beneficial to the plant itself. If I were going to try to keep the plant as healthy as possible till cut day I would increase the N if I increased the grow light spectrum.

 

[OldMedUser]

MostlyCrazy! +Rep.

I might just add the extra 400W MH to see what happens. I'm thinking, drain half the nutes that are getting old but still at 1000 ppm or so and topping up with 1/2 strength flowering mix of all three AN nutes.

Can't do too much damage at this stage. A lot of the colas are still growing flowers and the trichs are almost all still clear after 68 days at 12/12.

What the hey. Another twist to the grand experiment. lol

 

[MostlyCrazy]

Let me know what happens and if you notice an big difference.

 

[TheAnswer1776]

Awesome thread Roseman!

As I'm going to build a veg room next to the room I have I plan on using a combination of 4' fluorescents and CFLs for lighting chores in there. Chamber for clones, one for mother(s) and room for a couple of bubbler tubs. Going to have to punch a few 6" holes in existing walls for ventilation.



About this part. I did have my 400W MH added to my 2-400W HPS for a few days but figured adding it late in flowering might push the plant into thinking it was summer again and inhibit flowering. It was getting too warm in the grow room too with 3-400W lights. Time to upgrade my ventilation system.

So do you think maybe I should change to

A) 1000W MH for the end of days here

B) 1-400W HPS + 1-400W MH

C) 2-400W HPS (current set-up)

D) 1-400W MH + 1-400W EYE Hortilux running in HPS ballast.

E) 2-1000W MH + 2-400W HPS + 1-400W MH + 2-150W HPS and an assortment of 4' florescents and a half dozen 23W CFLs. ;0)

Probably get up in the morning to a house full of pot smoke and a serious if not fatal case of the munchies if I pick option E. lol

for the great info! Rep if I could. 5 stars at least.

C'ya.

Hey Labrat, I can tell you after doing extensive research on HID's, that contrary to the belief that bigger is better, most now agree that multiple lower watt HID's are better than a single 1000W. This is for several different reasons.

1. With more fixtures you can move lights and evenly distribute light better
2. With the lower watt(400, 600W), you can place closer to the canopy so there is alot less lumen loss
3. With the multiple lights you can add them as needed therefore not wasting energy

These conclusions are what brought me to my purchase of a 600W HPS. They are supposed to be the most effecient. Having the MH through flower is fine and alot of people reccomend the mixed spectrum. The increased blue light during flower aids in trich development from what I have read. I am assuming that option E was for your warehouse grow?

 

[Roseman]

Wouldn't you know that THEANSWER would have a great Answer!

And Mostly Crazy ! How is he ALWAYS right???

 

[FryingPanFlyer]

I was invited here to show a cfl light fixture I made a few weeks ago. I can't take credit for the idea, Matagrowa developed the idea, I just copied his work. Thanks again Mata for the inspiration.

My task was to construct a fixture for holding (8) 55w cfl's that are to be used in my veg. closet.

The most important part of my visit to the hardware store was finding what sockets they carried. My store had sockets that were wrapped in rubber, I didn't need the rubber, but it made for a nice fit. These sockets fit into the 1 1/4" pvc best. Matagrowa used 1" pvc because that's what his sockets fit into, but he did use a little electrical tape to snug up the socket's fit in the pvc. I'm happy with the 1 1/4" because it gave me more room to cram all the wires into.

I used the lamp cord due to it's flexibility. Mata used romex, a very hard, stiff wire that would be difficult to manipulate into the T's. Lamp cord is much more flexible making it much easier to work with.

By the way, those yoyo's that I'm hanging the fixture with is great! They are spring loaded so you just tighten the wing nuts to set the drag and you can hold a fixture that's up to about 22 lbs. if I remember correctly. I just lift the fixture to work on the plants, and pull it back down when I'm done.

The parts list:

(2) 4' pieces of 1 1/4" pvc
(8) 1 1/4" pvc t's
(4) 1 1/4" pvc L's
(8) lamp sockets
20' of 16/3 lamp chord
wire nuts
electrical tape
(4) #8 x 1/2" pan head screws
(1) 24" section of galvanized vent pipe
~4' chain
(4) 8" zip ties
(1) can of flat white spray paint

A couple of pics of the finished fixture:

 

[FryingPanFlyer]

Now to construction:

I first cut (10) 2 1/2" pieces of pvc, these will be the connectors for the socket holding T's and the corner L's. I determined this length by putting sockets into two T's and then measured the spacing between the lamps, adding for the amount of pipe going into the T's and L's I came up with 2 1/2". You will need to adjust this length to fit the size lamp you select.

I took an L, added a connector, then I took a T and placed a socket into the end and threaded the wires out the other end, refer to the first picture. In this picture I'm wiring the first two sockets together. You string them in parallel, that is you connect the black to black and white to white for the length of the fixture. The first connection you make, (do the same for the other side of the fixture) will have three wires bound together, the black (say) from the first light, the black from the second light and then the lamp cord I used to string them all together. Be careful with the lamp cord, it is only one color, I bought white. But they make the plastic coating on one strand smooth and the other is ribbed for identification.

After you have connected the first two sockets all the rest of the connections will consist of the lamp wire coming from the previous connection, the new socket and then the lamp wire going to the next connection. I made all connections using both wire nuts and electricians tape. I didn't want to have to take the damn thing apart to trouble shoot if it didn't work.

Proceed to make all the connections for both sides of the fixture. This really isn't very hard at all, it just takes some patience and time. I was cutting about 9" pieces of the lamp cord to make the running connections, that length gave me enough wire to work with but still not too much to cram into the pvc pipe for each connection.

After completing both sides of the fixture you need to determine the length of the end pieces that will define the width of the fixture. I placed the bulbs I'm using in the sockets to see how long to cut the end pieces. I left about 1" between the bulbs, this was just a guess, but it seems to have worked out fine. I then tied the wires coming from both sides of the fixture together, drilled a hold in the end pvc and pulled them out. This is the one place I missed in my material buying calculations. I only bought 10' of the lamp cord which only left me 4' sticking out of the fixture when done. I'd suggest you leave at lest 6' out, 10' would be better. If you buy 20' of lamp cord you will have plenty left over.

You'll notice that the only screws I used were to fasten the L's at the corners, these connections seemed to be pretty loose so I used the screws. The other fittings were plenty tight so I left them free so I can make adjustments to the lamp orientation if I want to in the future.

I then used these screws to fasten the hanging chains to the fixture. I made them long enough that when I hooked up to my hangers the chains would be approx 6" above the finished hood. Sorry but I didn't measure this length, just held it there and did what looked best. Just make certain the chain on both sides are the same length. Though that's not a deal breaker either, you can make up for it.

Next step was to put on the hood. I bought a piece of 8" dia galvanized metal duct pipe. I painted the underside with the flat white spray paint to aid the reflectivity. Then I drilled holes in the metal in the four corners and attached the reflector to the fixture using the zip ties.

This is a very simple fixture to make. You can make it any size, mine turned out to be 23" wide and 24 1/2" long. Just small enough to fit into a standard residential clothes closet. Be sure to verify the size of your lamps prior to cutting any material, those 2 1/2" i used may not work for you.