The CFL "12-Pack" Grow Light How-To:

[George Parker]

Hello, This is my first post so I thought I might as well try and contribute to this awesome forum the best I could.

After researching many designs for my CFL light fixture and seeing all the great work contributed by you the members, this is what I came up with using SketchUp:

The final product was a little different but the overall design remained pretty much the same. With the 23W 1600 lum CFLs I'm using, this will put out 19,200 lumens and 276 watts. All with very little heat. I wanted each bulb to have a reflector to force the light down, since these bulbs shoot so much light from their sides and not their bottoms. I chose to use white vinyl for the reflectors because of the low thermal conductivity.

**Please note, you will be working with power tools and electricity. Be safe and have fun with it!**

Tools Used:
Cordless Drill
Chop/Miter Saw
Wire Strippers
Wire Crimpers
Hammer

Materials Used/Needed:
1 PC. 2x4, cut to 24 5/8"
1 PC. 1/4" - 1/2" Plywood cut to 23"x15 3/4" (I used a piece of scrap 1/4" particle board I had that was shorter than the full width, the demensions given are for a true fit)
1 10' White vinyl rain gutter cut into 12, 7" PCS.
12 light socket cleats
12, 1/2" wood screws
28 Drywall screws
24 Blue ring terminals (16-14 GA.)
8' extension cord (14/2)
2 Screw Eyes
~10' of 14 GA wire cut to the following:
12 PCS cut to ~4"
12 PCS cut to ~6"
2 wire nuts (I love the beige ones, good for 18-8 AWG)
1, 1/2" staple
12, 23W CFL's (I am going to run 8 6500K /4 2700K for Veg, and reverse for Flower)
NOTE: Look for the Edison "Discount" CFL Packs. I found mine at a local Goodwill Store and picked up 48 23W 2700K Bulbs for $23.99 OUT THE DOOR!:

Now on to the build!

After cutting the 2x4 and the top pc, screw the top piece to the 2x4 using 4 of the drywall screws. (The 2x4 is longer for a reason, just center the top section)

Cut the rain gutter into 12, 7" pieces:

Don't eat the man-made snow! ::

Lay the wood top down and evenly place the 7" sections along the 2x4 and fasten to the top sheet with one 1/2" screw per piece (12 total):

Install the light socket cleats with the remaining screws. I drew the center line along the length of the 2x4 then centered each socket in the gutters as so:

Now pull up a chair, sit down and start cutting and splicing the wires:

Install the wires:

Cut the female end off of the extension cord and pull the two wires ~3" apart, then strip the ends and connect them. NOTE: the skinny prong on a two-prong plug is the "HOT" and the fatter one is the NEUTRAL. The "HOT" side of the light socket is usually indicated by a darker color metal, in my case the hot side was "Gold" and the neutral is "Silver". Make sure you connect the right wires to each other. You should end up with 2 groups of 3 wires each.

Then get out that heavy duty staple and hammer it to the 2x4 making sure to only SNUG it up to the wood! Don't beat the heck out of it or you can damage/cut the wire.

Now flip the fixture over and install the screw eyes in that little spot we left on top of the 2x4:

Install your bulbs, plug that girl in and enjoy!

The light is plugged into a surge protector that is plugged into a GFI outlet.

My trusty cell phone took all of these pics. I'll post up some pictures of how much light this thing kicks out when my camera is done charging.

Thanks for stopping by, if you have any questions/suggestions , ask/tell away, and thank you for posting your ideas and engineering, it was what inspired this build.

 

[Giantsfan24]

Although I'm going with HID..I've been seeing such awesome results from CFL grows that I've been wondering why not go CFL, save some electricity and I could go HPS for flowering...

My main concern is that you can't buy great fixtures like this and I don't feel comfortable enough with electrical wiring to venture into creating my own...until I saw this!!

Dude, seriously this is the best fixture I've seen in all of the months of research on several sites..it's because you didn't post this earlier that I went HID! You bum!!! (j/k)

But seriously...nice work...awesome getting reps on your first freakin post..NICE WORK!! Friend up yo!

Is it possible to go higher watt bulbs?



One question...is this grounded? Does it need to be? What is the total cost of the fixture to build?

 

[George Parker]

Although I'm going with HID..I've been seeing such awesome results from CFL grows that I've been wondering why not go CFL, save some electricity and I could go HPS for flowering...

My main concern is that you can't buy great fixtures like this and I don't feel comfortable enough with electrical wiring to venture into creating my own...until I saw this!!

Dude, seriously this is the best fixture I've seen in all of the months of research on several sites..it's because you didn't post this earlier that I went HID! You bum!!! (j/k)

But seriously...nice work...awesome getting reps on your first freakin post..NICE WORK!! Friend up yo!

Is it possible to go higher watt bulbs?



One question...is this grounded? Does it need to be? What is the total cost of the fixture to build?

Thanks for the kind words and the Rep! I was in the same boat with the "great light search". I got the idea from these forums and just added what I thought would benefit my needs. I'm designing my grow box around this for my first grow, should have the box built over this weekend. SCROG with a DWC/Bubbler system for two plants. I figure if I can grow two with CFLs, I'll move onto more and brighter lighting.

As for high power lights, I don't see why this design couldn't be modified to take larger/higher wattage bulbs. Just a matter of adding a few inches to the dimensions . I have no idea how much heat this can take, but it stays cool to the touch no matter how long it's on with the 23W bulbs. 12 42W CFLs would be sick. Not sure if it would work off the top of my head but it would equal around 500 watts and over 32,000 lums! But at that point in the cost arena, it might be cheaper to just go HID. At around $10.00 for one, 12 42W bulbs are $120.00.

Prices will vary, but I would say the cost to purchase everything is around $80.00 minus the bulbs. With bulbs ~$130.00 total. The cleats were ~$40.00, the gutter was only $5.00 for 10' at Lowes. The wire, extension cord and connectors were ~$18.00, The screw eyes were $1.00 at WallyWorld. I had the wood, screws, wire nuts and the staple (less than $15.00 to buy).

The light sockets I used were designed as a two wire only (Hot/Neutral) just like a household lamp. I'm running a surge protector with a built in ground as well as a GFI receptacle to handle any power spikes. The fixture itself is not grounded.

Hope I answered your questions and thanks for the warm welcome.

Here are some pics of the fixture in action:

The reflectors don't cast any shadows at all! The light softens the further away it gets. (man I need to paint my garage!)

@ around 1' off the ground, it lights up my entire garage floor while resting on a tote:

Up close:

Have a good one!

 

[Giantsfan24]

Thanks for the kind words and the Rep! I was in the same boat with the "great light search". I got the idea from these forums and just added what I thought would benefit my needs. I'm designing my grow box around this for my first grow, should have the box built over this weekend. SCROG with a DWC/Bubbler system for two plants. I figure if I can grow two with CFLs, I'll move onto more and brighter lighting.

As for high power lights, I don't see why this design couldn't be modified to take larger/higher wattage bulbs. Just a matter of adding a few inches to the dimensions . I have no idea how much heat this can take, but it stays cool to the touch no matter how long it's on with the 23W bulbs. 12 42W CFLs would be sick. Not sure if it would work off the top of my head but it would equal around 500 watts and over 32,000 lums! But at that point in the cost arena, it might be cheaper to just go HID. At around $10.00 for one, 12 42W bulbs are $120.00.

Prices will vary, but I would say the cost to purchase everything is around $80.00 minus the bulbs. With bulbs ~$130.00 total. The cleats were ~$40.00, the gutter was only $5.00 for 10' at Lowes. The wire, extension cord and connectors were ~$18.00, The screw eyes were $1.00 at WallyWorld. I had the wood, screws, wire nuts and the staple (less than $15.00 to buy).

The light sockets I used were designed as a two wire only (Hot/Neutral) just like a household lamp. I'm running a surge protector with a built in ground as well as a GFI receptacle to handle any power spikes. The fixture itself is not grounded.

Hope I answered your questions and thanks for the warm welcome.

Here are some pics of the fixture in action:

The reflectors don't cast any shadows at all! The light softens the further away it gets. (man I need to paint my garage!)

@ around 1' off the ground, it lights up my entire garage floor while resting on a tote:

Up close:

Have a good one!

Yeah baby...the 42w CFL's would be very sick and put out more lumens than my 250w HID setup with cost one hell of a lot more than $130 or even $200.

The cleats can handle that wattage? The lumens aren't the real issue but the PAR of the lights. I've been reading up on that but the results people get here with cfl's is ridiculous.

I got turned off to them though cause most of the setups look so ghetto AND the electrical is a bit intimidating. Yours looks trick, simple and could be way effective. I know I can build your design. The no shadows part is crazy!

The cool part, like you, is customizing it for the box. You can make it the exact dimensions of your area which is HIGHLY efficient use of space not to mention the profile is reduced...I just like the efficiency of the design.

How deep is it with the 23watters?

 

[PrairiePoet]

Great Design!!!
I've been thinking on re-doing my CFL lights, This gives me some new thoughts on how to do it.

Thanks,
Prairie

 

[George Parker]

The cleats can handle that wattage?

The cleats will handle 660W and 250V. I could run about 28, 23W bulbs, but that would be maxing out the sockets.

How deep is it with the 23watters?

The dimensions are 24 5/8" X 15 3/4" X 4" high

Great Design!!!
I've been thinking on re-doing my CFL lights, This gives me some new thoughts on how to do it.

Thanks,
Prairie

Thanks Prairie, I've been watching your SCROG grow and can't wait to start mine.

~dirt

 

[PrairiePoet]

Thanks Prairie, I've been watching your SCROG grow and can't wait to start mine.
~dirt

I'm on the third grow since my journal. Learn more and more from the site here. This one is not doing well, mostly because of the cold we've had. But I should still do well.

For small spaces (hell maybe even for large spaces) I think SCROG is a great way to go.

I'll keep an eye out for your journal.

Prairie

 

[Giantsfan24]

hey dirt..thanks for the awesome post here, again. You've inspired me. I'm rigging up my own light and have a question for you.

I went out and bought 2 bathroom vanity light fixtures.

I mounted those to a center board shown here:

Two things:

I was trimming some excess sheet metal from the fixture and accidentally cut one of the wires between sockets.

I had a barrel connector, spliced the wire cleanly and connected them together. Would it be better to use a wire nut here? Or shitcan it and just get a new fixture?

Is this safe?? Or should I find another way to connect them? The connection from socket to socket is soldered so it appears not screwed or I'd replace the wire entirely.

Additionally, there are ground wires on the fixture, two of them. The original was connected to a facade then to the sheet metal of the fixture and then one for the ground connection. Since I won't be using the facade, I only need one ground wire from the fixture to the ground connection correct??

I consider it extremely fortuitous that you would happen by my thread just when I need advice on electrical stuff. I've always shyed away from electrical, shocking I know , but am capable.

 

[YardDog35]

A big on this thread

That is the best cfl fixture I have seen so far! You put some thought into this and it payed off. As far as cost it is a lot cheaper compared to name brand T-5 fixtures. With an even canopy this would do just as well in my opinion.

Plus rep to you my friend, not only for coming up with this design, but for sharing it with rest of us.

Good luck to you on all your future grows.

hey dirt..thanks for the awesome post here, again. You've inspired me. I'm rigging up my own light and have a question for you.

I went out and bought 2 bathroom vanity light fixtures.

I mounted those to a center board shown here:

Two things:

I was trimming some excess sheet metal from the fixture and accidentally cut one of the wires between sockets.

I had a barrel connector, spliced the wire cleanly and connected them together. Would it be better to use a wire nut here? Or shitcan it and just get a new fixture?

Is this safe?? Or should I find another way to connect them? The connection from socket to socket is soldered so it appears not screwed or I'd replace the wire entirely.

Additionally, there are ground wires on the fixture, two of them. The original was connected to a facade then to the sheet metal of the fixture and then one for the ground connection. Since I won't be using the facade, I only need one ground wire from the fixture to the ground connection correct??

I consider it extremely fortuitous that you would happen by my thread just when I need advice on electrical stuff. I've always shyed away from electrical, shocking I know , but am capable.

Good score Gfan

Hope dirt does not mind me putting in my 2 cents here. I would wire nut those wires back together. I like those butt connectors for low voltage only. When it comes to AC always use the correct size wire nuts. Like dirt said the beige ones work well for the application. If there is not enough slack in the wire (my guess is no) use a piece of 'patch' wire the same gauge with two wire nuts to complete the connection. Heat is our major concern with electricity. If the connection cannot let the 'current' flow through properly heat develops...heat can lead to fire. I know we are talking about 23 watt bulbs that draw very little amperage, but safety first.
And yes, you are correct on the ground wire.

 

[Giantsfan24]

Good score Gfan

Hope dirt does not mind me putting in my 2 cents here. I would wire nut those wires back together. I like those butt connectors for low voltage only. When it comes to AC always use the correct size wire nuts. Like dirt said the beige ones work well for the application. If there is not enough slack in the wire (my guess is no) use a piece of 'patch' wire the same gauge with two wire nuts to complete the connection. Heat is our major concern with electricity. If the connection cannot let the 'current' flow through properly heat develops...heat can lead to fire. I know we are talking about 23 watt bulbs that draw very little amperage, but safety first.
And yes, you are correct on the ground wire.

Yeah...that's what I thought yard...especially considering I've ordered 42watters! HELL YEAH!

I think I'm just going to replace the fixture. It's only $19 at Lowe's and that is a small price to pay for safety. I'd replace the wire but it's soldered on and I just don't want to take a chance of f'in something up.

As a reflector, I'm going with the white board used for dry erase boards. Thin, highly reflective and durable.

Do you think these will put out a lot of heat? I've read that cfl's put out between 30% to 70% less heat as they fire differently than HID and incandescent but with (12) 42w that's over 500watts and over 30K lumen it could get hot??

I've got to get this box finished in the next week..damnit!!

 

[YardDog35]

Yeah...that's what I thought yard...especially considering I've ordered 42watters! HELL YEAH!

I think I'm just going to replace the fixture. It's only $19 at Lowe's and that is a small price to pay for safety. I'd replace the wire but it's soldered on and I just don't want to take a chance of f'in something up.

As a reflector, I'm going with the white board used for dry erase boards. Thin, highly reflective and durable.

Do you think these will put out a lot of heat? I've read that cfl's put out between 30% to 70% less heat as they fire differently than HID and incandescent but with (12) 42w that's over 500watts and over 30K lumen it could get hot??

I've got to get this box finished in the next week..damnit!!

Those 42 watters get hot bro. CFL's are cooler yes, but in a small space in numbers they create some heat. My tent has a footprint of 36"x18" and is 5' or so tall. When I ran 8 23 watt cfls and exhausting 150+ cfm's temps were about the same as my air cooled 400 watt hood. You are in the garage though so I think cfl's will be more affective in your environment.

 

[George Parker]

A big on this thread

That is the best cfl fixture I have seen so far! You put some thought into this and it payed off. As far as cost it is a lot cheaper compared to name brand T-5 fixtures. With an even canopy this would do just as well in my opinion.

Plus rep to you my friend, not only for coming up with this design, but for sharing it with rest of us.

Good luck to you on all your future grows.

Good score Gfan

Hope dirt does not mind me putting in my 2 cents here. I would wire nut those wires back together. I like those butt connectors for low voltage only. When it comes to AC always use the correct size wire nuts. Like dirt said the beige ones work well for the application. If there is not enough slack in the wire (my guess is no) use a piece of 'patch' wire the same gauge with two wire nuts to complete the connection. Heat is our major concern with electricity. If the connection cannot let the 'current' flow through properly heat develops...heat can lead to fire. I know we are talking about 23 watt bulbs that draw very little amperage, but safety first.
And yes, you are correct on the ground wire.

Thanks for the comments and the rep!

It's kinda like the old saying, "It takes a village to raise a...Plant!" This forum is like a WWC (World Wide Collective), it's awesome that there are sooooo many ideas that spawn sooooo many more ideas.

To giantsfan: yarddog hit the nail on the head with the wiring, thanks again yarddog! I can't wait to see how your lights turn out, that's going to be a lot of light.

 

[Giantsfan24]

Thanks for the comments and the rep!

It's kinda like the old saying, "It takes a village to raise a...Plant!" This forum is like a WWC (World Wide Collective), it's awesome that there are sooooo many ideas that spawn sooooo many more ideas.

To giantsfan: yarddog hit the nail on the head with the wiring, thanks again yarddog! I can't wait to see how your lights turn out, that's going to be a lot of light.

I just added a bunch of stuff to the box and it looks like the HID is going to work out after all...should've not been so impatient...it's a failing I have...

Box mods:

I replaced the 4" recirculating fan with a 6".

I added a speed controller to the intake fan. This will equalize the cfm of the box exhaust fan to maintain some negative pressure. I'm not too worried about negative pressure honestly as the cfm of the exhaust outweighs the cfm of the intake. The speed controller will also give me the option to "pump up the volume" if I need to..

I have another fan hooked up for odor control that will run only when needed so that will add to the negative pressure in the box. Because that will run independent of the thermal controller and go 24/7, I'll need a couple passive intakes but because this will only be the case with lights off, there won't be heat issues just air exchange issue. (this isn't a new mod)

I got my exhaust fan hooked up and it seems to be doing the job nicely.

The only real difference has been the 6" recirculating fan. Set on low, it seems to have made the difference. The ambient temp in the garage, I just tested it, is 55 degrees. That is normal for the garage. I've seen it down to high 40's but..

For now it looks like I'm in business. Should I keep the 2 dozen 42watters as a back up light in case my HID fails??

 

[George Parker]

I just added a bunch of stuff to the box and it looks like the HID is going to work out after all...should've not been so impatient...it's a failing I have...

Box mods:

I replaced the 4" recirculating fan with a 6".

I added a speed controller to the intake fan. This will equalize the cfm of the box exhaust fan to maintain some negative pressure. I'm not too worried about negative pressure honestly as the cfm of the exhaust outweighs the cfm of the intake. The speed controller will also give me the option to "pump up the volume" if I need to..

I have another fan hooked up for odor control that will run only when needed so that will add to the negative pressure in the box. Because that will run independent of the thermal controller and go 24/7, I'll need a couple passive intakes but because this will only be the case with lights off, there won't be heat issues just air exchange issue. (this isn't a new mod)

I got my exhaust fan hooked up and it seems to be doing the job nicely.

The only real difference has been the 6" recirculating fan. Set on low, it seems to have made the difference. The ambient temp in the garage, I just tested it, is 55 degrees. That is normal for the garage. I've seen it down to high 40's but..

For now it looks like I'm in business. Should I keep the 2 dozen 42watters as a back up light in case my HID fails??

Sorry for the late reply... Been driving the porcelain bus through flu town for the last two days.

I have been playing with air flow too. Just ordered a new fan for the DIY exhaust I am building, if it works out the way I think it will, I should get 250 cfm for about $30.00 and it runs on 12 VDC. I made some custom light traps for the two 78 CFM computer fans (intake/exhaust) I have, but am back to the drawing board to increase air flow. It's kind of a pain in the a$$ but it's fun to build things! Plus, now I have some extra fans to play with. I'll let you guys know how it works out and who knows.... I may have a second DIY thread soon!

giants: As for your CFLs; It's always nice to have a backup . One of the reasons I chose CFLs other than price are their simplicity.

Have a good one

 

[Giantsfan24]

Sorry for the late reply... Been driving the porcelain bus through flu town for the last two days.

I have been playing with air flow too. Just ordered a new fan for the DIY exhaust I am building, if it works out the way I think it will, I should get 250 cfm for about $30.00 and it runs on 12 VDC. I made some custom light traps for the two 78 CFM computer fans (intake/exhaust) I have, but am back to the drawing board to increase air flow. It's kind of a pain in the a$$ but it's fun to build things! Plus, now I have some extra fans to play with. I'll let you guys know how it works out and who knows.... I may have a second DIY thread soon!

giants: As for your CFLs; It's always nice to have a backup . One of the reasons I chose CFLs other than price are their simplicity.

Have a good one

Yeah I think so..having a back up is a good idea. At a minimum it will help out if I have a ballast failure or bulb failure. I'll be able to install quickly without missing too much.

You know what helped me out with temps is the recirculating fan. I had a 4"that really didn't do much so I replaced that with a 6" clip on and my temps came right under control.

I'm ready to grow...waiting on one piece of equipment then I'm grow journal bound!! YES!

 

[George Parker]

Good luck with the grow! I'm right behind you.
Also, where did you get your fan and thermal controller for your box?

 

[drkdiglr112]

Very cool bro great design I have been looking for something to use in my box but I think I am going to use your design

 

[George Parker]

Very cool bro great design I have been looking for something to use in my box but I think I am going to use your design

Thanks for visiting. If you have any questions please ask away.

I should finally have my power supply for my exhaust fan today (fingers crossed) so I can start my journal and show this thing in action.

 

[George Parker]

I love upgrades! I added a 120mm PC fan to each row of lights to help circulate the air inside the box. This light fills my grow box so I had to figure out a way to improve airflow while working in tight spaces, this is what I came up with and it works awesome.

They fans are mounted to a piece of 3/16" X 1/2" bar stock I had from another project. The bar is ~14" long and is mounted on the 2x4 with two wood screws.

My box is 27"W x 18" D x 48" H and this fixture blasts light everywhere. There is almost zero shadowing holding my hand between the light and the tub. After testing and testing and some more testing, I am finally ready to start my grow!

Sorry for the cell phone pics again, everytime I go to take pictures of this thing my camera batteries are charging..LOL (I take a ton of pictures).

The journal is about to start...stay tuned!

 

[PrairiePoet]

Waiting for your journal buddy.

Something I'll suggest for your next upgrade on the lights. For a better heat control, instead of using a flat board over the top, use some of the bar stock framing the whole thing. Cut thin slits or small holes in the plastic gutter (down towards where the socket is preferred). Then place a piece of thin wood, or even foam board over the top, with a hole in it (or two). Place your fans on those holes. Then you would be pulling the air from right around the bulbs, up and out. Add some ducting and push the air out of the box.

I really like your light fixture. Better than the power strip and plug sockets thing I was thinking of.

Prairie