Things to know about lighting .this link
Things to know about lighting
Color rating- Measured in Kelvin (K). The higher the number, the more bluish the light. 4000K-7000K is mostly on the blue side of the spectrum, while 3000K and under goes from a white spectrum, to a redder spectrum.
How much light is needed?
The minimum amount of light required by
marijuana plants is around 3000 lumens per square foot. However, it's not 100% 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 reflectivity of the grow box. The ideal amount is somewhere around 7000-10,000 lumens/sqft, and as long as the plants do not burn, as much light can be used as you want.
(*note, the sun produces about 10,000 lumens/sqft, on a sunny summer day).
Determining lumens for your grow area:
Determine the square footage of your area (example in a 4 foot by 4 foot area, there is 16 square feet)
If you have a 1000 watt High Pressure Sodium, that produces (approx.) 107,000 lumens.
Divide this by 16 (your square footage) 107,000 / 16 = 6687 lumens per square foot.
So just divide the total amount of Lumens, by the total amount of Sq ft, and thats 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, unless there is 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, so move the light up until your hand feels more comfortable. For seedlings and clones, I keep them a little further away from the light, because they are very susceptible to burning and drying out, at these stages.
Efficiency is very important when choosing a type of light. The wattage is not the most important thing, as you can see below, different types of light produce different amounts of lumens per watt. A 300 watt incandescent will produce about 5100 lumens. While a 300 watt Metal Halide (just an example, they do not come in 300 watts), will produce 27,000 lumens. Obviously far more efficient for growing, while still using the same amount of electricity.
Approximate light production:
Incandescents: 17 lumens/watt
Mercury vapor: 45-50 lumens/watt
Fluorescents: 60-70 lumens/watt
Metal halide: 90 lumens/watt
High pressure sodium: 107 lumens/watt
Incandescent lights: Incandescents are the most popular type of lights in the world. They may come advertised as incandescent, tungsten, quartz, halogen, or simply standard. The important thing about incandescents is this: they suck.
There are some incandescents which are sold as 'grow lights.' They usually have a blue coating and usually come in 60W and 120W sizes. While they may seem like a good choice to new growers, they are next to useless; they produce some light at a usable spectrum, but only have about a 5% efficiency and generate more heat than usable light. Most of us have these in our homes right now. Don't use them for growing, instead opt for a Compact Fluorescent as a cheaper but more efficient alternative.
Fluorescent lights: Fluorescents are a lot more useful than incandescents. Their efficient enough, and cheaper than HID lights. Compact fluorescent tubes are popular with growers because of their good output to size ratio. Compared to standard 4' tubes, compact fluorescent bulbs are smaller, and more can fit into a given area. Fluorescents are good for small grows on a tight budget, and for novice growers, since they do not require any special sort of wiring or understanding of the necessary bulbs for a given fixture, and are very widely available.
Fluorescent lights come in many different Kelvin ratings; often the spectrums are labeled on packaging as being 'cool white' or 'warm white.' Cool white is more blue, and is good for the vegetative stages of growth, and warm white light is more orange or reddish, and is best for the flowering stage.
High Intensity Discharge (HID) Lighting Systems:
Mercury Vapor (MV)
Mercury vapor lights are not the most efficient light for growing. They are very bright, and relatively cheap. They do emit light at the wavelengths necessary to support your plants growth, but not nearly as good as a MH or Hps light. Much of the light emitted by MV lights is bluish-white. Street lighting is what most MV lighting is used for.
Metal Halide (MH)
Metal halide lighting systems are optimal for use in the vegetative phase of growing. They emit mostly blue light, which encourages vigorous growth of foliage. They are very efficient, but can get rather expensive to start with; fluorescents may seem more appealing because of their lower price, and they are not much different when compared on a lumen-to-lumen cost level. These lights can be used through-out the grow, but will most likely result in light, fluffy buds.
High Pressure Sodium (HPS)
High pressure sodium lights emit mostly orange, yellow, and red spectrum light, which is perfect for the flowering stage of the plants growth. They are (in my opinion) the most efficient type of light available for any application. HPS lights can be used through-out the entire grow. They produce more dense and usually larger buds than any other light.
HPS lights are generally a little more expensive than MH systems of similar wattage. They are more commonly used by experienced growers because of their ability to produce tighter buds, higher lumen-output-per-watt, and will produce from start to finish.
I'll also add this graph below, i hope this post helps some of you out.
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<LI id=post_75698 class="postbitlegacy postbitim postcontainer">03-16-2007 04:13 PM
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roosterfish
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ive just changed to 250 wats of them nlite cfls red and perple wud love to know if anyone cud fill me in on any ifo about um
<LI id=post_75700 class="postbitlegacy postbitim postcontainer">03-16-2007 04:15 PM
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mogie
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Contributed by: removed user 08/18/04
submitted: July 6, 2003
This is a compilation of basic information on fluorescent lighting that I have gathered over a period of several months.
artwork provided by: ReSoNiC420
What is a fluorescent light?
A fluorescent light is made up of a glass tube coated with phosphor, which is filled with a mixture of gases. When electrical current is applied, it "excites" the gases, causing the tube to glow brightly. ie: to "fluores".
Why do fluorescent lights have different colors?
The tubing is coated with phosphor, which will determine the color of the bulb.
What diameters of fluorescent tubes are available?These are the most widely used diameter fluorescent tube size is T-5, T-8 T-10, T-12. Bulb sizes (meaning diameters) vary from .25 up to 1.5 inch, the larger in diameter the larger the fluorescent.
What length is most used?
There is a wide variety of lengths from 6 to 96 inch, the most widely used is a 48 inch fixture.
What wattage is there to use?
Fluorescents come in a wide range of watts any where from 4 to 214 watts that I have found.
Why does my bulb flicker?
Fluorescent tubes are rated by hours, these hours vary by the manufacture, the most common rated hours are from 6000-22000 hrs. The bulb flickering can also be caused by a poorly seated tube (poor receptacle contacts), a ballast or starter going bad or a tube wearing out such as shown in the photograph.
How do I dispose of these lights when they are broke?
Although commercially generated fluorescent lights are required by law, to be handled separately from general trash. Residents are allowed to dispose of them with the rest of their household garbage.
Where can I purchase fluorescent tubes, and how much do they cost?
Fluorescents can be purchased at all home improvement centers, hardware stores, and most pet supply stores or you can go to internet sites such as
http://www.1000bulbs.com/. The cost may vary depending were you reside, but the typical cost is a few dollar's for a pack of two bulbs.
Who manufactures these lights?
These are the most reliable companies on the market today: Sylvania, Westinghouse, General Electric.
What are lumens?
Lumens are the unit of measure that state the amount of light output produced by a light source. The higher the lumens, the greater the light output. The standard fluorescent tube should produce at least (3000-3300) lumens.
How can I optimize the light output?
You can help reflect the light out of each tube, by using metal foil tape as a reflector, attached directly to the tube as shown in this faq.
click here Using clear plastic safety sleeves over the fluorescent tubes allows you to recycle the metal foil reflective tape.
What is a Kelvin scale?
One way light is measured is on a Kelvin scale. A Kelvin scale expresses the exact color the bulb emits. Bulbs in the range of 2700 to 6500 on a Kelvin scale is ideal for growing
marijuana. Plants respond not only to the quantity of light, but also the quality.
* artwork provided by: ReSoNiC420 (click chart to enlarge)
What color spectrums are available in fluorescent bulbs?
Fluorescent bulbs have the most range of spectrums than any other bulb. The spectrum comes in various spectrums, determined by the type of phosphor with which the bulb is coated. The following fluorescent types are as listed, along with what they may accomplish for you.
Full spectrum fluorescent bulbs have all the colors of the Kelvin scale. This bulb is good for vegetation stage. Note: This spectrum fluorescent is used in hospitals nationwide in helping people with "depression".
Wide spectrum fluorescent bulbs will restrict development of side branching, helps plants mature faster. This fluorescent is high in the red, orange and yellow color range. In fact, this fluorescent is the highest than all other fluorescent bulbs. As a matter of fact, this fluorescent is much like an HPS color range, which makes it the best all around choice for flowering stage.
Daylight spectrum fluorescent bulbs are very high (if not the highest) in the blue range on the Kelvin scale. This fluorescent promotes an arctic blue look. I suggest this fluorescent during vegetation stage.
Cool spectrum fluorescent bulbs will promote multiple side growth, nice green foliage. This fluorescent is high in the blue range, giving off a bright white appearance. I suggest this fluorescent for vegetation stage.
Warm spectrum fluorescent, will promote extra thick stems and branches, and will give you about 5% denser buds than other spectrums. This fluorescent is high in the red range on the Kelvin scale.
In the old school of fluorescent growing, an even mix of warm white and cool white tubes has been proven to be the best combination of light spectrums to use for flowering stage. If wide spectrum bulbs are unavailable in your area, then this is the combo to use.
Do fluorescent tubes need air circulation? Fluorescent tubes do get warm, but not if they have adequate air circulation. A simple fan blowing over the fixtures as shown, will help a great deal to cool the tubes.
If its done properly, any stray foliage that comes in contact with the tubes will not be harmed.
and have no partner so ill be set this time
