f40t12 offers a slightly larger surface area and is a cheaper setup all-around.
the new "energy saving" 4ft t12 bulbs are i think something like 36w a piece.

You'll have to look at individual bulb and ballast combinations since they vary so much. A 32W T8 is designed to be roughly equivalent to a 40W T12, each producing nearly 3,000 lumens.

Question:

If you can produce the same amount of light using 32W per tube or 40W per tube which one would you choose?

depends what I'm growing and how the bulbs are positioned. In an older hood i constructed for a growbox i had t12 bulbs double stacked supplemented with t8 in the corners

probably the t12 though as there is no way you will notice a diff. in your elec. bill if only using 1 bulb. and initial investment is a bit less as well as replacement bulbs (only by a few cents, sometimes on sale though)

the one thing i like about the t8 is that the temperature is easier to follow as it is usually printed right on the bulb as opposed to cw ww etc. on shoplights.

t8 are mostly used in commercial/industrial applications where many many multi-bulb high bays/lay-ins burn all day long. In this situation wattage becomes an issue, and many business are pursuayed to change over after consulting a lighting rep....
for our home purposes unless redesigning the lighting plan of your house use the t12 bulb.

Cost of electricity over the full life of a 32W bulb is about $65. Cost for the 40W bulb would be about $80. If you plan on using the bulb until it croaks then the initial bulb cost becomes almost irrelevant. Many growers replace bulbs after about 5,000 hours, then the cost of the bulb starts to become an issue. A T8 will always have the advantage that you can cram more into the same space to produce a more intense light.

Lifestarter mentions an interesting point. Many "F40T12" bulbs aren't 40W at all. They are nominal replacements for a 40W bulb and may only use 36W-38W. Similarly, an F32T8 may actually consume more like 34W. What a nightmare!

If you are only using one bulb, then it doesn't make a bit of difference. I have 12 fixtures (24 bulbs) running 12 - 16 hours a day so it matters to me. I have measured power use a couple of times at about 68W per fixture.

The HD T8 fixtures run $5-$8 each. I'm surprised that T12 fixtures are cheaper.

I didn't check, but I suspect that the 36W energy saver bulbs use less electricity because they emit less light.

gbrendemuehl wrote:

"The HD T8 fixtures run $5-$8 each. I'm surprised that T12 fixtures are cheaper."

According to the package, the HD $7.98 fixtures w/electronic ballasts will support either T8 or T12 bulbs.

rok,
difference is the quality from HD usually is chincy at best.

I can also buy a solar light set of 6 for 24.99 for my front path but in a year at best they'll be gone or lawn ornaments. Disposable lighting. hmmmm nice marketing concept homey D;

stamp out the cheapest product possible, consisting mostly of poly and cheap steel materials, along with chinese sweat shop engineered electronics etc under misleading names like "Hampton Bays"
Did you know that HD IS hampton bays?

homedepot=mickie mouse lighting
period.
do it right the first time.

Extraordinary lighting stores and supply houses in our area that have staff on hand for field-educated face to face explinations anytime include

Aetna-hicksville,
Creative Lighting-mineola,
star&son-franklin square,
Duplex
michaels
Revco out east
too many to list
but
i have had terrible experiences at just about all nassau county HD, the lighting center, national, expressions, walmart, kmart, and countless others.

nowadays its hard to find a real old time store with cutting edge product that can help like these. You will have no problem finding wire, ballast,nuts,and sockets for custom reflectors/boxes and greenhouses where a remote ballast is golden.

Lowes stores seems to be a better place to start though they just started to pop up recently round these parts so i can say little. creative is where i have shopped for 30+yrs.

Good luck on your journey into lighting hope this can steer some folks into the light it took an hour to write up i hope you can appreciate what I am getting at.
peace
LS

rok,
difference is the quality from HD usually is chincy at best.

I can also buy a solar light set of 6 for 24.99 for my front path but in a year at best they'll be gone or lawn ornaments. Disposable lighting. hmmmm nice marketing concept homey D;

stamp out the cheapest product possible, consisting mostly of poly and cheap steel materials, along with chinese sweat shop engineered electronics etc under misleading names like "Hampton Bays"
Did you know that HD IS hampton bays?

homedepot=mickie mouse lighting
period.
do it right the first time.

Extraordinary lighting stores and supply houses in our area that have staff on hand for field-educated face to face explinations anytime include

Aetna-hicksville,
Creative Lighting-mineola,
star&son-franklin square,
Duplex
michaels
Revco out east
too many to list
but
i have had terrible experiences at just about all nassau county HD, the lighting center, national, expressions, walmart, kmart, and countless others.

nowadays its hard to find a real old time store with cutting edge product that can help like these. You will have no problem finding wire, ballast,nuts,and sockets for custom reflectors/boxes and greenhouses where a remote ballast is golden.

Lowes stores seems to be a better place to start though they just started to pop up recently round these parts so i can say little. creative is where i have shopped for 30+yrs.

Good luck on your journey into lighting hope this can steer some folks into the light it took an hour to write up i hope you can appreciate what I am getting at.
peace
LS

lifestarter,

I am the proud owner of several of these cheapie fixtures. I do understand that there are better quality units on the market but these come at a greater cost too. Many of the folks in this forum use these inexpense HD fixtures with electronic ballasts and swear by them. If they do happen to burn out, they can be replaced for another $7.00. Not a big investment.

Also, many of the people in this forum only use there indoor light setup for 2-3 months a year. Investing more $$ is simply not wise.

If I get to a point where I will be growing larger plants year round, I'll consider a more elaborate setup. Until then, my Home Depot specials are just fine ;-)

Regards,

~Rokal

sorry 4the double post
i thought this is the growing under lights forum. thought it would be applicable seeing how the sun dont shine inside..
maybe you think you are in the propagation seed/plants forums?
whatever you say, if they were so good you wouldnt need to waste time finding mail order parts like the thread below this one which has someone backing my point that the ballast you are currently using is a piece of junk and the parts/bulbs are manufactured by the depot under fake names... just read it yourself
quote from next thread in forum in response to someone who can not find a part:
" * Posted by: MaineMan z5a ME (My Page) on Wed, Mar 23, 05 at 17:55

Doug,

"Is there a phone number or address of Commercial Electric on the box?"

There is no phone number on the boxes for either model number. It does say that "Commercial Electric is a registered trademark of Homer TLC, Inc." The 140-904 boxes give this address:

Commercial Electric
2455 Paces Ferry Road NW
Atlanta, GA 30339

That address is also Home Depot's address, so apparently Commercial Electric and Home Depot are very closely related. The ballasts say SUNPARK, Torrance, CA so I suspect SUNPARK is a separate company that supplies ballasts to Commercial Electric.

The assembly instructions give a Customer Service phone number of 1-800-345-0542

MM "

Here is a link that might be useful: to each his own..

Lifestarter,

Please reread the entire post that you are quoting "MaineMain" from.

You can find it here:

Home Depot Commercial Electric 140-904 Availability

They are looking to purchase the $7.00 HD overdrivable fixture but they are having trouble locating it. They are NOT looking to purchase replacement parts. Many members of this forum, including MaineMan, have had these fixtures running for years with no problems.

This is a very appropriate forum and I would love to hear your suggestions for an alternative overdrivable setup with similar to slightly higher cost but much better quality. I am not a lighting expert so if you could enlighten me as to how a more expensive fixture will do a better job, I'd be delighted to listen.

I'm all ears (pun intended) ;-)

Peace.

Give me any fluorescent fixture that has a replaceable ballast and I can find a way to make it super bright, 32.00 dollars max.

Which is Brighter? I'll tell ya....

Brightness Wise
F40T12 + Magnetic Ballast = Normal Light
F40T12 + Electronic Ballast = Slightly Reduced
F32T8 + Magnetic Ballast = Don't Attempt!
F32T8 + Electronic Ballast = Slightly Brighter

Efficiency Wise
F40T12 + Magnetic Ballast = Normal
F40T12 + Electronic Ballast = Better
F32T8 + Magnetic Ballast = Don't Attempt!
F32T8 + Electronic Ballast = Best

Tube Brightness
40W T12: Normal
34W T12: Pathetic **see reason
25W T12: Slightly Dimmer
32W T8: Slightly Brighter

**34 watt tubes are not good candidates for plants because in order to get to their full brightness they must be warm, but since they use less energy, they do not get as warm, thus they bubble and never get to full brightness unless there are NO drafts. The slightest temp drop will cause reduced light output.

****Maybe I should make a website on fluorescent lighting for plants.****

My advice is to use T8's, especially if you care about cost for usage.

Also the brightness differs by brand and spectrum.

-j-

lol we should have a light showdown.
i'll take you up on that lighting
website idea, email me maybe we can
work with this GoDaddy! hahahahaha
www.whichisbrighter.ws on sale now for 4.99/year
roflmfao

I have always used the T12 40w 4' bulbs for my plants and cuttings. I decided I wanted a wider reflector in place of the standard 7" ones. So I now have a 13" wide reflector and it uses T8 bulbs. To me they are not nearly as bright as the 40w T12. I would rather of had the wide reflector with T12 but it doesnt seem to be available. Indeed they may spread out more light to the area needed just not as much light. I tried this once before with a standard shoplight and T8 bulb it was the same effect for me.

That's why the make light meters. a T8 and a T12 of the same manufacture and the same color temp. The same reflector. All of which make a difference. The T8 is always brighter according to my meter. You can find T8 up to 3300 lumens but most are 2800 for 32W a T12 is around 2300 at 40W, Now there are also HO T8 with 4300 lumens and 44 watts.I found HO T12 that use 60W but only produce 3000 to 3500 lumens.
Also the Cri makes a difference in how bright they LOOK, and the color temp. Daylight 5000k to 5700k look way brighter than warm white 2700k to 3500k.