Help with cfl's

[jillielover]

How can I tell the light spectrum of my cfl's? I bought two ge 26w cfls recently to add to my other lights, but there was no Kelvin number anywhere on the package or the light itself.... Is there anyway to tell if it is red or blue?

[gonnagrow]

I could be wrong but I would assume they are around 4100k ish as they would be close to standard cool white tubes.

Gg

[celticweedlover]

Does it say either 'warm white' or 'cool white' on it?
If its Orangey/red'y then its a warm white/2700k(i think)
If its Whitey/bluey then its a cool white/6400k (could be a daylight spec too)
Hope that helps!
CWL

[gonnagrow]

Aye Celt, the fluoro's I have seen are warm white 3100k (red), cool white 4100k (red/blue ish) and daylight ultra/deluxe 6500k (blue). I use a mix of two 4100's and four 6500's for vegging.

Gg

[celticweedlover]

youre right Gg, I got kinda mixed up earlier on
Heres some info for ya jillielover!
CWL

The color of a light source entails a complicated relationship of different factors, that are important in determining the right light source for your garden. The advantage of Metal Halide lamps is that they provide high-quality, crisp white light in a variety of different color temperatures that meet the needs of many different users.

Correlated Color Temperature(CCT)

The first factor in choosing a color of lamp is to determine whether you need a warm or cool light source. The CCT, expressed in Kelvin degrees, relates to actual thermal temperature. If you've ever seen a piece of metal being heated, you know that as the metal gets hotter, it's color changes. The CCT rating of HID and flourescent light sources indicate how warm or cool the light source is. For instance a lamp with a CCT of 2700 Kelvin is considered warm; with a CCT of 4200 Kelvin is considered neutral; and one of 6000 Kelvin is considered cool.


Spectral Energy Distribution

When you look at a light source, you perceive seeing a single color, but you are actually seeing thousands of hues. The combinations of different wavelengths of light make up the color we see. The relative intensity of the various wavelengths are used to determine a light source's Color Rendering Index(CRI).


Color Rendering Index(CRI)

The CRI is an indication of a lamps ability to show individual colors relative to a standard. This value is determined from a comparison of the lamp's spectral distribution compared to a black body at the same color temperature. Light sources, such as metal halide lamps, are rated with a CCT; however, CCT does not provide any information on the quality of the color. For this, a CRI is also necessary. In general, the higher the CRI rating of a lamp, the better the different colors will show.


5K - 7K Kelvin: Strong Blue Light
Promotes bushy growth. Ideal for rapid growth phase of plants.
Greatly enhances all-around plant growth when used with super
high output, high pressure sodium or 3K warm metal halide lamps.

4.2K - 4200 Kelvin: Cool white Flourescents
Can be used as supplimental blue lighting when used with a 3K
source.

4K - 4000 Kelvin: Neutral Metal Halide
Best single source for plant growth, producing shorter, bushier
growth than 3700 Kelvin and color rendition. Used in general
plant lighting.

3.7K - 3700 Kelvin: Softer Metal Halide(coated)
This coated lamp is used in general plant lighting and for more
rapid growth than 4000 Kelvin produces.

3K - 3200 Kelvin: Warm Metal Halide
Highest photosynthetically active radiation (PAR) value of all HID
lighting for all phases of plant growth. PAR watts account for the
nutritional value of light and are a direct measure of the light
energy available for photosythesis.

2.7K - 2700 Kelvin: High Pressure Sodium Lamps
Redder color mix, used for propagation, blooming, supplemental
greenhouse lighting.

[BostonKid]

Hey man, I just got the same exact thing that you're talking about and im using it to grow my clones right now. It is a cool white which would be more on the blue side and works better for the vegitative stage. If you want a red spectrum which works better for flowering, you can buy a full spectrum cfl.

[celticweedlover]

Ok im after confusing every1 or sumtin
A 'Daylight Ultra/Deluxe" is 6400/6500k, which is completely in the blue end of the spectrum!
A 'cool white' is 4100/4200K, which is basically in the middle but tilting slightly more bluey!
A 'Warm White' is 3100/3200k, which is in the orange/red end of the spectrum!

For veg i was using 104w 6500k floros' and it gave some sick results in keeping it bushy.Then i added in 76w 3100k Cfl's around the plant To help for flowering!
CWL

[jillielover]

Can you give me descriptions of what each of those bulbs looks like, maybe pictures? Or can you give me a place in Connecticut USA I coyuld buy those?