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A basic Guide to CFLs (compact fluorescent bulbs)

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#1 Mr Pothead

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Posted 24 May 2014 - 02:32 PM

A basics guide to CFLs CFL guide.

Here's a quick guide to enlighten (grroooaannn) those that are new to growing and want some CFL info.


CFL's - The General facts.

CFL = Compact Flourescent Light

They grow perfectly good MJ- quality IS comparable to Anything a hid can produce.
Plants take longer to grow- Flowering time is increased by anything from 1 - 3 weeks (compared to hid -)

Yields are decreased. This statement is slightly misleading, even tho yeilds are reduced compared to hid's, 0.5-1g per watt CAN be produced with a sea of green in a perpetual grow. either way buds can be big, tight, and potent. (strain & grow experience dependant of course) (tho not as tight as HPS, but as potent)

Cfl's run cooler. this means that we can place them as close as 2-3cm from the canopy/margins, they require far less extraction power to keep the room cool, as much as 80% imo. (tho due to the nature of growing air movement/replacement IS required)
Cfl's use less electricity. yes they do, but not much (5% watt for watt- i'm guessing here). and in cost watt for watt,its not much at all.

Why use CFLS?

CFL's should be used for growing, when space or stealth becomes an issue or funds are lacking and light is needed to grow. Due to the thermal nature of these bulbs, they can be used in places that the hot lights cannot, spaces under 1.5m square can now be used for growing WITHOUT the need for expensive extraction and cooltubes.

Money issues.
A CFL Grow can be up and running for under the price of a gram of weed! Yep, using the HOUSEHOLD CFL'S that YOU have, you can grow POTENT, MJ in a small box with just a few 20w CFLS and a couple of p.c fans. Now EVERYONE can grow MJ, yes even YOU, just browse our beginner topics here at The Green Circle and grow some potent bud in no time (well.... 3 months ish from seed..), this was NOT as possible/viable/accesable just 10 years ago.

Heat: worried about heat extraction? CFL's are very cool running (considering) and up to 250w of CFL can be safely used in a small space with just PC fans as extraction and circulation.

Stealth. Got a spare chest of drawers? old wardrobe? turn it into a grow room! Cfls make this possible. with little extraction to worry about, PC fans run quetly in the background, of course, with canna there is SMELL, and some strains stink to high heavens, and no matter how stealthy you are. they give the game away.

Space. like stealth, when space is an issue, cfls can be used as a viable way to grow in small spaces that need to be "closed" for one reason or another, or just because the space you have is no higher than 800mm (its possible to grow in a p.c case..)

Supplemental lighting. CFL's are an Excelent source of lighting to ADD to a current HPS grow. thay can be added in all sorts of places to get that light right in there with awesome results.

First time growing. Dont want to spend hundreds on that kit and find growing just isnt for you. start small and cheap with a CFL, and if you like it-work your way up- or not, whatever the case may be. ...... Growin with CFL's.

If your planning on using them then you need to know HOW to use them, as growing with CFL's requires some basic strategys.

Keep Bulbs close: try and keep the bulbs as close to the foliage as possible. 20w CFL's can be as close as 1-2cm, 250W CFL's need to be between 2-5 inches from the canopy- MAX. this is WHY cfl's work so well. due to the square inverse law, we are losing MUCH MUCH less light than we would if the bulb was 18 inches from the plant. they (the CFL manufacturer's) spout 100% par too, whatever that means!

Plants should be topped and or trained. although its possible to grow BIG main colas with buds 1 foot high and as fat as a fist, its EXTREMELY inneficient with cfl's, the main cola needs to be side lit at least on 1 side and turned at least daily- 180 degrees. its far easier to just TOP the main cola and low stress train the resulting nodes out with garden wire. this way you "spread" the plant like a spider, and each nodes gets max light, and max light = no wastage!

Thinning. Penetration of cfl's is weak when compared to Hids, so to let the light penetrate in, selective thinning or pruning can help increase yields when some strains grow extra dense in the centre mass. i`ve flowered a 5 foot sativa (topped (twice)) under 1x 250w CFL, had buds grwing in the top 1-2 foot (it got lollypopped) and pulled almost 3 ounces including testers and serious noob errors. (she was thinned, topped,over pruned, over+under nuted, had spider mites-that got chemicaly nuked, 3 or 4 repots and 3 or 4 diff types of soil... but i digress.)

Sea of green, Growing a perpetual sea of green with CFL's can bring excelent results with both yeild and time. using a mature "mother" plant for clones vegging seperately, and puting 5 or so clones into flower every 2 weeks str8 after rooting, in small deep pots (no bigger than 1.5litre), each clone finaly pulling at LEAST 10g dry (18 inches max), will pull in on average 50g per 2 weeks. esp once you have "honed in" on your envoiroment and plants.

P.C fans (4 inch & 6 inch) are great for air cooling the top of the canopy, and provide more than enough thru-flow to disperse any heat build-up and or stale air. a couple of passive intakes 4 inches square, and 1 or 2 P.C fans as extractors, is more than suitable to cool most

Closed CFL grow spaces and cabs. again, a couple in the box to keep the air moving is great and can be as close as a few inches from the plant with zero fan burn.

Red or blue. what colour light is it you have?, usualy it says on the box, and below are some of the standard names used.
Warm/Red = 2700K Cool/Light white = 4150K Noon Sunlight= 5300K Blue CFL = 6100K Daylight white = 8500K

If you are just thinking of using 1 colour for veg AND flower, try for red. if you HAVE to use a blue CFL for flowering its not the end of the world and great bud is possible

Cfls are a viable alternative for those with SMALLER spaces, Lighter Pockets, first time growers, supllimental lighting, and stealth boxes. use em and see how gr8 they are. (for copious amounts of bud)

Hids are for those that can afford it and have the space. slightly better yields, want a quicker flowering period, (and copious amounts of bud and then some)
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