CFL Growing -- What type of light to use when flowering

P

presto

Member
I will soon be attempting my first grow using maybe 2 cfl's (about 35 watts each) for one plant. I will be adopting the common 18/6 method for vegging, and 12/12 for flowering. However, when I switch to 12/12 I have heard it is better to switch the type of light I am using as CFL's are best for the vegetative period. So my question: For various reasons I want to stick with using CFL's throughout. Is there any types of CFL's on the market producing different types of light? Or is there any good methods that you may know about that will assist with the flowering period?? Any help is appreciated -- Cheers!:joint:
 
paddy510

paddy510

Well-Known Member
youll want the 2700k ones, they give off more of a yellow orange light compared to the 6400k ones which give of a more blueish white light.
youll also want higher watt lights for flowering, like 42w or more if you can get them. use as many as you can, when you start flowering keep using the two you have now aswell as the 2700k ones.
 
Mystik

Mystik

Active Member
yeah the basic theme is pretty simple higher (color range) numbers for veg lower numbers for flowering.
You always want as much light as possible, it will encourage thick healthy growth.
 
Roseman

Roseman

Elite Rolling Society
42 watt average $10.00 each

65 watts, = $19.99 average price ($16.95 now at Lowes and Home Depot)

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

105 watt average $34.95 to $38.99 each


Or Look for Clamp Reflectors and Bulbs together:




CFLs come in 15, 26, 42, 65, 85 and 105 watts and recently last year, even larger wattages.
The 26s and smaller are not as efficient to me.
26s to 85s do not put out any noticable heat unless oyu use a lot 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 each.
65 watts are abut $24 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 $10 heavy duty clamp reflectors at Lowes, Home Depot or Walmart. They also offer a cheaper $8 reflector but it is smaller and flimsey.

With CFLs, you need the DUAL SPECTRUM, red and blue spectrums, high and low kelvins.. 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, called kevins.
CFLS come in 2700 kevins, 3000, 4100, 5100, and 6500.
2700k is for BLOOM OR FLOWERING , 6500k is the VEG Spectrum. The others are "MID" spectrums or in between.
IF you sue the MID-range bulbs (4100) then also use the 6500 and 2700s.
In outdoors, the sun produces different rays in the spring (VEG Rays called Blue) and late summer for Bloom spectrum, the RED spectrum. (see more below)

CFLs are new on the 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 equivalant. For example, a 15 watt CFL bulb puts out 60 watts.

Spiral and Tube type CLFS emit LIGHT FROM THE SIDES, NOT THE ENDS OR TIPS.

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

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).

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.

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 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.


Just like everything else, available grow lights are evolving. Remember how the sun produces 10,000 lumens per square foot in the mid-summer. Well, today there are CFLs that can actually duplicate those lumens. If you can not grow under the sun, then bring the sun inside. Yes, you can have 20,000 lumens covering the entire grow space with the new 105 watt per bulb CFLs. Three of these bulbs in the proper reflector actually yields 20,000 lumens.

Low heat, energy efficient light bulbs for use with Stealth Hydro Dual Spectrum Lighting Systems. Available in blue (vegetative) and red (flowering) spectrums.
I like being able to move the CFLS around, and lower them down in between the plants, the clamp- reflectors are just $10 each.Lowes, Walmart, Home Depot:



and get one of these extensions:

and if you want to add two lights to a reflector, you get a Y spliter.

This pic shows both COOL WHITE and WARM WHITE, or high and low kevin bulbs:


One of many mistakes I have made over the years, is I wish I had labeled or dated my bulbs.

I have some 65 and 85 watt bulbs, and they have seen 6 GROWS. I wish I knew how to distinguish them from the new ones.

I highly urge everyone to date-label your bulbs.
 
MJforTN

MJforTN

Member
okay so im running two t8 fluorescent 32W one is cool white, the other is sun light... the sun light is clearly more of a blue white color, where the cool white is more of a white!! LOL... anyways i am growing two plants off of that... the plants are growing, but slowly!! so im thinking i need to get more light!! any advice... pics on my profile under 1st grow!!
 
Roseman

Roseman

Elite Rolling Society
MJforTN said:
okay so im running two t8 fluorescent 32W one is cool white, the other is sun light... the sun light is clearly more of a blue white color, where the cool white is more of a white!! LOL... anyways i am growing two plants off of that... the plants are growing, but slowly!! so im thinking i need to get more light!! any advice... pics on my profile under 1st grow!!
Click to expand...
You need to read this:
CFL Tutorial -
 
Roseman

Roseman

Elite Rolling Society
MJforTN said:
:confused: im confused???? why do i need to read about CFL's?? just wondering?? :peace:
Click to expand...

you asked a question about LIGHT and that is what that thread is all about.

And the name of this thread is CFL Growing -- What type of light to use when flowering
 
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