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- Message-ID: <011304Z15011995@anon.penet.fi>
- Newsgroups: alt.drugs
- From: an180198@anon.penet.fi
- Date: Sun, 15 Jan 1995 01:11:27 UTC
- Subject: FAQ-Growlights (updated 1-12-95)
-
-
-
- someone put this updated FAQ into the hyperreal archives?
-
-
- GROW LIGHTS FAQ (Last update, January 12th, 1995)
-
- Maintained by Samoka Z. Boul
-
- The purpose of this FAQ is to help limit the spread of misinformation
- regarding effective artificial lighting systems, and help those who
- choose to grow plants under artificial lighting make an informed
- decision before buying a lamp.
-
- Most of the information contained in this FAQ comes from printed
- sources, and some from electronically distributed files. Very little
- comes from my own experience, as I have not owned, used or examined
- most of the systems discussed here.
-
- This FAQ is not going to tell you how to use your lamp, that
- information can be found in most grower's guides.
-
- Introduction:
-
- There are three major types of lighting systems available right now:
- incandescent, fluorescent, and high intensity discharge. Incandescent
- lights are horribly inefficient (especially the screw-in "grow bulb"
- type) and really not an acceptable option for plant growth. Although
- they are inexpensive to purchase, their cost of operation makes them
- the costliest source of light.
-
- Fluorescents:
-
- Until the early 1980's most indoor growers used fluorescent lights to
- illuminate their garden. These tubes have tremendous advantages over
- incandescents. They emit about 3 times as much light as an
- incandescent (given the same wattage), and the light spectrum is one
- that plants con use more effectively.
- However, they do certainly have their limitations. Light is emitted
- over a large area, so it is not concentrated. Because of this, the
- lights have to be hung very close to the plants (usually within 2" or so
- from the grow tips), and constantly moved to accommodate plant growth.
- This makes garden maintenance rather difficult, even when the lamps are
- hung on chains.
- Florescents are, however, very useful in cloning, and starting
- seedlings. Because in these stages, a plant is not growing vertically
- very quickly, the disadvantages of moving the lights are reduced. They
- also put out a more gentle light than the HID lamps, and release less
- heat. The fact that they produce less heat is very important to those
- growing in enclosed and not-especially-well ventilated spaces.
- If you choose to use fluorescents, it is best to purchase the 'cool
- white' variety. The ones that are sold as grow lamps (including
- grow-lux, vitalite, etc.) are much less efficient than a standard
- fluorescent, and just do not put out enough light to be useful. The
- slightly different spectrum produced by these lamps does nothing for
- most plants. Some growers have reported excellent results by using a
- mixture of cool-white and warm-white lamps in a florescent fixture.
-
-
- High Intensity Discharge Lamps (HID's)
-
- High intensity discharge lamps are easier to use, and more
- efficient. Low wattage HIDs are sometimes sold for household outdoor
- use. Large Wattage lamps are used for lighting streets, parking lots,
- stadiums and other large areas. They come in two basic flavors:
-
- METAL HALIDES or MH lamps emit a white light that looks slightly
- bluish. They are used to light stadiums, convention centers,
- gymnasiums, and other large areas where a natural looking light is
- desired.
-
- HIGH PRESSURE SODIUM or HPS lamps emit a pink or amber light. They
- are used for lighting parking lots and other areas where the color
- of the light is not important. HPS units are much more efficient
- than MH ones, producing more light and less heat per watt of energy
- consumed. They are often used alone with no detrimental effect on
- the plants, and will promote faster plant growth than MH lamps
- during both vegetative growth and flowering. Combinations of
- bulbs are _NOT_ required, as the HPS lamp does produce all of the
- light spectrums necessary for healthy growth.
- There is a relatively now type of HPS lamp that has become
- available. It is called the San Agro lamp (Look in _Grower's Edge_
- Magazine for more than a few distributors. Basicly the designers of
- this lamp took a 400w HPS lamp, and added another 30W element to it,
- However, this new element puts out blue light, to help fill in the
- parts of the spectrum that a standard HPS is missing. I've never
- actually seen one of these bulbs, so I can't tell you about how
- efficient they are, but if a Hydroponics magazine thinks they're
- terriffic, I can't disagree.
-
- MH lamps are available in 175,200, 400 and 1000 watt sizes. HPS
- lamps come in 50, 75, 150, 400 and 1000 watt sizes. San Agro comes in
- 430w only, but it works with a 400w HPS ballast. Each lamp
- requires its own ballast, which comes with the fixtures that are
- designed to use these lamps, and are also available separately.
-
- The following chart shows how much light each lamp emits, and the area
- that it covers adequately:
-
- Lamp # of Lumens Sq. Ft
- ---- ----------- ------
- 4'FL (CoolWhite-40W) 2,960 1-2
- 8'FL (CoolWhite-75W) 5,800 2-4
- MH 175W 14,000 5-10
- MH 400W 40,000 12-20
- HPS 70W 7,600 3-6
- HPS 150W 16,000 6-11
- HPS 400W 50,000 15-30
-
- Gardens should receive 1000-3000 lumens per square foot. Successful
- gardens usually are lit at around 2,000 lumens per square foot. During
- the vegetative stage, plants stretch out when they receive low levels
- of light. During flowering, the flowers are looser and sparse.
-
- So what is the best lamp for grow6ing? It depends on your budget. HPS
- lamps are by far the best overall, but they are also the most costly to
- purchase and setup (although some less honest growers have a tendency
- to steal them from college campuses and the like). However, they are
- the cheapest to operate, and the utility savings does eventually add
- up.
-
- A quick warning: At least in the US, there are large government
- agencies whose only purpose is to eliminate the growth of marijuana.
- Although purchasing a high powered lighting system does not mean that
- you will be growing pot (and many people grow other things
- artificially), it is still not a really good idea to link your name
- with the purchase of one of these lamps (especially the larger ones).
- Go into the store knowing exactly what you want, pay for it in cash,
- and do not give them your name (or give them a false one if they even
- ask). Most lighting distributors will not ask any questions.
-
- I wish you a healthy and happy crop.
-
- - Samoka.
-
- ==
- The author is a freelance writer/UNIX guru, who doesnt know anything
- about what grows under these lamps, except for Tomatoes, living
- somewhere on this side of eternity. Don't even think about asking for
- an email address.
-
- "Think about the future, for it is where we will spend the rest of our lives"
-
-
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