how many cfl bulbs for flower?

[highsakite]

Hi all,

i would like your suggestions about how many cfl bulbs (and which size)
to use when i switch to flower

the box is 3 ft by 2 ft by 6 ft, tho i don't really think i'll use all the height...

I want to wire up the cfls to two round reflectors, thinking one in center socket and 3-4-5 (more?)
attached to the rim horizontally

which would be the best bulbs for lumen coverage?

45w, 26w, or 20w

there are six plants in the box right now, but i expect to thin that out once i switch lights and identify the boys

thanks for any help and suggestions

cheers

 

[PeytonManning]

If you can, you'll want at least 150 watts per plant. 26 watt have the best lumen per watt or something like that. It'll take quite a few bulbs, so do the math before you buy any and see if you can get an led for same price. You'll also want your CFL bulbs about 2 to 6 inches away

 

[highsakite]

Thanks Peyton,

wow, that will be a shitload of bulbs and sockets n stuff
or my math is wrong: 150w per plant = 900w all up, right?
which means around 36 or so bulbs...which seems like a lot...
as well, if that number is correct, that would take around $130 or so to set it up...

i'm not even sure i could fit that many in there...

cheers

 

[PeytonManning]

You can use less if you top and train the plants flat, scrog em out. Perfect grow style for CFL bulbs

 

[doobie gillis]

Greenmans grow guide says !0,000 lumens minimal for plant growth.Those 24w cfl bulbs (100w equivalent) put out 1600 lumens,so you need 9 bulbs at least.Here is what I would do.Get those y shaped bulb adaptors (1 bulb to 2).$2.50 at home depot,connect 3 together.now you screw that into fixture and you can screw in 4 bulbs in 1 fixture and your only drawing 96w per fixture.3 fixtures and your putting out 19,200 lumen.In flower use more soft white bulbs than bright white,say 8 to 4.....good luck

 

[SixthEddie]

I have to disagree with 150 Watts per plant, i have always heard and followed 100 watts per square foot. Works great for me!

 

[Antics]

100w /plant in Veg 150w /plant in Flower is a quick guide assuming an average Veg time, and training a flat canopy. These are also the minimum suggested. I used these numbers for my own grow with a decent level of success.

The CFL, T5, T8, T12 number is 65w/square foot if I remember correctly, but plant size changes things.

When you're growing your plants tall, without training, the 65w/sqft, and even 100w/sqft numbers become useless, as the CFL bulbs have a limited level of penetration, you end up with a concentrated level of light at the top, and the bottom doesn't see as much. Then you start adding bulbs to compensate for this, all hung at varying differences, and when all is said and done, you may end up with more bulbs than needed for a similar grow when trained flat. It seems to be mostly about training the plant to take advantage of what the particular lighting system has to offer.

With CFLs I like a shallow, but wide canopy.
With my LED I grow a deeper canopy, and also just was wide.
I haven't grown with HIDs, but with those, I'd let the plant grow a bit taller.

For my last CFL grow, I ended up using 14 bulbs, and a total of 361 watts. 2 plants in soil, and I yielded a little over 3 ounces.

As Peyton pointed out, make sure you add up the cost of what all the bulbs will cost you, plus all the fixtures, plus splitters, plus wiring. And also take the power consumption into consideration, you might be better off buying an LED when all the costs are compared.

An LED panel that would produce comparable, or better results than a CFL grow will use somewhere around half the power, and produce a lot less heat. Both of these factors helped sway my decision. But you can also grow some really nice plants with CFLs too.

SweetSue proved that with her CFL auto grow in organic soil here: Sweetsue's First Grow - Stealthy Trio of Autos Under CFLs She ended up with something like 4.5 ounces from just 2 plants.

Every type of lighting can work, whether you choose CFL/Fluorescent, LED, or HID. You just have to find that sweet spot for each plant, and they'll do the rest.

 

[highsakite]

thanks for all the great suggestions folks

i went to the light shop and got some figures, which would you recommend?

At the moment there are 4 x 45w daylight @ 2970 lm (11,880 lm in total)
if i simply swap these for 4 x 45w warmwhite @ 2925 lm (11,700 lm)
these bump my elo by $40 or so a month

or there are these, all warmwhite figures;

28w spiral @ 1680 lm
20w spiral @ 1300 lm
18w spiral @ 1200 lm

i also saw these led bulbs,

Osram Led Star Classic A40, warmwhite was; 6w @ 400 lm

Katie Racer Led A60, warmwhite 8w @ 650 lm

the daylight bulb from Katie Racer was; 8w @ 800 lm

cheers

 

[highsakite]

I went to the lighting street here and found some 23w spiral cfls that give 1600 lm.

I bought 10 (16000 lm total) and all the necessary fixtures n whatnot

I have put together two reflectors for flowering, the central bulbs are 23w daylight
the others are 23w warmwhite

will this be enough? I have 4 spare sockets that can be added also.

cheers

 

[doobie gillis]

I'm no expert but that looks good to me.Plants look good.Thats more lumens than a 150w hps.