What are my options?



CFLs come in 15, 26, 42, 65, 68, 85 and 105 watts and recently last year, even larger 200, 250 and 300 wattages.

The 26s and smaller are not as efficient to me. The 15 watt bulbs are a major waste in my opinion.

26s to 85s do not put out any noticable heat unless you use dozens 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 to $10 each.

65 watts are abut $17 to $20 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 $12 Heavy Duty Clamp reflectors at Lowes, or Home Depot. Walmart sells a cheaper $8 reflector but it is smaller and flimsey and does not last. The plastic breaks easily.





DUAL SPECTRUM

With CFLs, you need the DUAL SPECTRUM, red and blue spectrums. 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 of the bulb, called kelvins.

CFLS come in 2700 kevins, 3000, 4100, 5100, and 6500.

Low Kelvin bulbs, like the 2700k is for BLOOM OR FLOWERING, 6500k is for the VEG Spectrum. The others are "MID" spectrums or in between.

IF you use the MID-range bulbs (4100) then also use the 6500 and 2700s for a balanced spectrum.

In outdoors, the sun produces different rays in the spring (VEG Rays called Blue) and late summer rays for the Bloom spectrum, the RED spectrum. The sun also produces green, and orange rays, but plants do not use them.



CFLs are fairly new on the grow-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 equivalent . For example, a 15 watt CFL bulb puts out 60 watts equvalent .



Spiral and Tube type CLFS emit LIGHT FROM THE SIDES, NOT THE ENDS OR TIPS. Spirals do project light in a circle more than the tube type.



YOU CAN GET SPIRAL CFLS (15, 26, 42, 65, 85) AND TUBE TYPE CFLS (105, 250, 300).



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).

Contracy to "talk" you CAN have too much light.)



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.







Note on HIDs contributed by PurpDaddy:

When given the choice of only one light, most marijuana growers will choose an HPS, High Pressure Sodium grow light over MH, Metal Halide, because HPS lights are more efficient (larger harvest).

You can't use a standard high pressure sodium bulb in a metal halide fixture, but you can use a metal halide bulb in a high pressure sodium fixture of the same wattage.

There are special hps bulbs that can be used in a mh fixture and vice-versa. But these conversion bulbs cost about double the price of a standard bulb.

With HID Lights:

A 250 watt fixture will supply enough light to cover a 2.5 foot by 2.5 foot grow area. (6 plants or less)

A 400 watt fixture will supply enough light to cover a 4 foot by 4 foot grow area. (12 plants or less)

A 600 watt fixture will supply enough light to cover a 5 foot by 5 foot grow area. (18 plants or less)

A 1000 watt fixture will supply enough light to cover a 6.5 foot by 6.5 foot grow area. (30 plants or less)



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 with HIDs 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. Placed too far away, and you will get undesired STRETCHING. (defined later)



I can safely place my 42, 65 and 85 watt bulbs one and a half inches near the plant.

I put the 105 and 200 watt bulbs three to four inches near.



How do I decide which lights to use?

Efficiency is very important when choosing a type of light. The wattage is not the most important thing, different types of light produce different amounts of lumens per watt. For example, a 300 watt incandescent will produce about 5100 lumens. (not that you can grow with incandescent bulbs) 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.

Can you afford to VENT the HEAT out of the grow area and cool the area? (HID)

Are you on a budget? (CFL)



Approximate estimated 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: Incandescent bulbs 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 incandescent bulbs when it come to growing is simply this: they suck. Using incandescent bulbs to grow plants is like trying to flag down the Space Challenger with a burnt out match! You can do it, but it won't work. 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, CFL, as a cheaper but more efficient alternative.



Fluorescent lights: Fluorescents are far more useful than incandescents. They are efficient enough, and much less expensive than HID (High Intensity Discharge) lights. Compact fluorescent tubes, (commonly called CFLs) are popular with growers because of their good output to size ratio. Compared to standard 4 foot tubes, CFLs are smaller, more easily moved, and more can fit into a given small area. CFLs 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 the small wattage ones (23, 42 and 65) are very widely available. Fluorescent lights come in many different Kelvin (spectrum or color) ratings; often the spectrums are labeled on packaging as being 'cool white' or 'warm white.' Cool white is more of the blue spectrum, and is good for the vegetative stages of growth. The bulbs are ultra white. Warm white light is more reddish in spectrum, and is best for the flowering stage. The bulbs are almost cream colored.



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 for Vegging or GROWING, while 3000K and under goes from a white spectrum, to a redder spectrum and is best for BLOOMING or FLOWERING.

There is NOT one CFL bulb for both spectrums, two different kelvin bulbs are needed.



One of many mistakes I have made over the years with growing is I wish I had labeled or dated my bulbs. I highly urge everyone to date-label your bulbs. A flourscent bulb can still light up and show LIGHT, but be worn out and not be putting out HALF the lumens it did, when it was new.