The Unsorted BBS Collection/thegreatunsorted.tar/thegreatunsorted/texts/txtfiles_misc/pot11

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                 -+- The Merry Pranksters from Menlo Park -+-
                               10.1990.01.01.11

                 Marijuana Grower's Handbook - part 11 of 33
                               by pH Imbalance
                            "Lighting and Lights"

                                     from

                         Marijuana Grower's Handbook
                         [Indoor/Greenhouse Edition]
                                 Ed Rosenthal


   Green plants use light for several purposes.  The most amazing thing that
they can do with it is to use the energy contained in light to make sugar
from water and carbon dioxide.  This process is called photosynthesis and it
provides the basic building block for most life on Earth.  Plants convert
the sugars they make into starches and then into complex molecules composed
of starches, such as cellulose.  Amino acids, the building blocks of all
proteins, are formed with the addition of nitrogen atoms.
   Plants also use ligh to regulate their other life processes.  As we
mentioned earlier, marijuana regulates its flowering based on the number of
hours of uniterrupted darkness.  (See part 25, Flowering)
   Sunlight is seen as white light, but is composed of a broadf band of
colors which cover the optic spectrum.  Plants use red and blue light most
efficiently for photosynthesis and to regulate other processes.  However,
they do use other light colors as well for photosynthesis.  In fact, they
use every color except green, which they reflect back.  (That is why plants
appear green; they absorb all the other spectrums except green.)  In
controlled experiements, plants respond more to the toal amount of light
received than to the spectrums in which it was delivered.
   The best source of light is the sun.  It requires no expense, no
electricity, and does not draw suspicion.  It is brighter than artifical
light and is self regulating.  Gardeners can use the sun as a primary source
of light if they have a large window, skylight, translucent roof, enclosed
patio, roof garden, or greenhouse.  These gardens may require some
supplemental lightning, especially if the light enters from a small area
such as a skylight, in order to fill a large area.
   It is hard to say just how much supplemental light a garden needs.
Bright spaces which are lit from unobstructed overhead light such as a
greenhouse or a large southern window need no light during the summer but
may need artificial light during the winter to supplement the weak sunlight
or overcast conditions.  Spaces receiving indirect sunlight during the
summer may need some supplemental lighting.
   Light requirements vary by variety.  During the growth cycle, most
varieties will do well with 1000-1500 lumens per square foot although the
plants can usemore lumens, up to 3000, efficiently.  Equatorial varieties
may develop long internodes (spaces on the stem between the leaves) when
grown under less that bright conditions.  During flowering, indica varieties
can mature well on 2000 lumens.  Equatorial varieties require 2500-5000
lumens.  Indica-sativa F1 (first generation) hybrids usually do well on
2500-3000 lumens.
   Some light meters have a foot-candle readout.  Thirty-five millimeter
cameras that have built-in light meters can also be used.  In either case, a
sheet of white paper is placed at the point to be measured so it reflects
the light most brilliantly.  Then the meter is focused entirely on the
paper.
   The camera is set for ASA 100 film and the shutter is set for 1/60
second.  A 50 mm or "normal" lens is used.  Using the manual mode, the
camera is adjusted to the correct f-stop.  The conversion chart, 10-1, shows
the amount of light hitting the paper.
   Most growers, for one reason or another, are not able to use natural
light to grow marijuana.  Instead, they use artificial lights to provide the
light energy which plants require to photosynthesize, regulate their
metabolism, and ultimately to grow.  There are a number of sources of
artificial lighting.  Cultivators rarely use incandescent or quartz halogen
lights.  They convert only about 10% of the energy they use to light and are
considered inefficient.

                           Chart 10-1: Footcandles

               +----------------------+----------------------+
               | 1/60 Second, ASA 100 | 1/125 Second ASA 100 |
               +--------+-------------+--------+-------------+
               | F-Stop | Footcandles | F-Stop | Footcandles |
               +--------+-------------+--------+-------------+
               | f.4    | 64          | f.4    | 128         |
               +--------+-------------+--------+-------------+
               | f.5.6  | 125         | f.5.6  | 250         |
               +--------+-------------+--------+-------------+
               | f.8    | 250         | f.8    | 500         |
               +--------+-------------+--------+-------------+
               | f.11   | 500         | f.11   | 1000        |
               +--------+-------------+--------+-------------+
               | f.16   | 1000        | f.16   | 2000        |
               +--------+-------------+--------+-------------+
               | f.22   | 2000        | f.22   | 4000        |
               +--------+-------------+--------+-------------+

On some cameras it is easier to adjust the shutter speed, keeping the f.stop
set at f.4 (at ASA 100):

                       +----------------+-------------+
                       | Shutter Speed  | Footcandles |
                       +----------------+-------------+
                       | 1/60           | 64          |
                       +----------------+-------------+
                       | 1/125          | 125         |
                       +----------------+-------------+
                       | 1/250          | 250         |
                       +----------------+-------------+
                       | 1/500          | 500         |
                       +----------------+-------------+
                       | 1/1000         | 1000        |
                       +----------------+-------------+
                       | 1/2000         | 2000        |
                       +----------------+-------------+


                              FLUORESCENT TUBES

   Growers have used flurorescent tubes to provide light for many years.
They are inexpensive, are easy to set up, and are very effective.  Plants
grow and bud well under them.  They are two to three times as efficient as
incandescents.  Until recently, fluorescents came mostly in straight lengths
of 2, 4, 6, or 8 feet, which were placed in standard reflectors.  Now there
are many more options for the fluorescent user.  One of the most convenient
fixtures to use is the screw-in converter for use in incandescent sockets,
which come with 8 or 12 inch diameter circular fluorescent tubes.  A
U-shaped 9 inch screw-in fluorecent is also available.  Another convenient
fixture is the "light wand", which is a 4 foot, very portable tube.  It is
not saddled with a cumbersome reflector.
   Fluorescents come in various spectrums as determined by the type of
phosphor with which the surface of the tube is coated.  Each phosphor emits
a different set of colors.  Each tube has a spectrum identification such as
"warm white", "cool white", "daylight", or "deluxe cool white" to name a
few.  This signifies the kind of light the tube produces.  For best results,
growers use a mixture of tubes which have various shades of white light.
Once company manufactures a fluorescent tube which is supposed to reproduce
the sun's spectrum.  It is called the Vita-Lite and works well.  it comes in
a more efficient version, the "Power Twist", which uses the same amount of
electricity but emits more light because it has a larger surface area.
   "Gro-Tubes" do not work as well as regular fluorescents even though they
produce light mainly in the red and blue spectrums.  They produce a lot less
light than the other tubes.
   To maintain a fast growing garden, a minimum of 20 watts of fluorescent
light per square foot is required.  As long as the plants' other needs are
met, the more light that the plants receive, the faster and bushier they
will grow.  The plants' buds will also be heavier and more developed.
Standard straight-tubed fluorescent lamps use 8-10 watts per linear foot.
To light a garden, 2 tubes are required for each foot of width.  The 8 inch
diameter circular tubes use 22 watts, the 12 inch diameter use 32 watts.
Using straight tubes, it is possible to fit no more than 4 tubes in each
foot of width because of the size of the tubes.  A unit using a combination
of 8 and 12 inch circular tubes has an input of 54 watts per square foot.
   Some companies manufacture energy-saving electronic ballasts designed for
use with special fluorescent tubes.  These units use 39% less electricity
and emit 91% of the light of standard tubes.  For instance, an Optimizer
warm light white 4 foot tube uses 28 watts and emits 2475 lumens.
   Both standard and VHO ballasts manufactured before 1980 are not
recommended.  They were insulated using carcinogenic PCB's and they are a
danger to your health should they leak.
   The shape of the fluorescent reflector used determines, to a great
extent, how much light the plants receive.  Fluorescent tubes emit light
from their entire surface so that some of the light is directed at the
reflector surfaces.  Many fixtures place the tubes very close to each other
so that only about 40% of the light is actually transmitted out of the unit.
The rest of it is trapped between the tubes or between the tubes and the
reflector.  This light may as well not be emitted since it is doing no good.
   A better reflector can be constructed using a wooden frame.  Place the
tube holders at equal distances from each other at least 4 inches apart.
This leaves enough space to construct small mini-reflectors which are angled
to reflect the light downward and to seperate the light from the different
tubes so that it is not lost in crosscurrents.  These mini-reflectors can be
made from cardboard or plywood painted white.  The units should be no longer
than 2.5 feet wide so that they can be manipulated easily.  Larger units are
hard to move up and down and they make access to the garden difficult,
especially when the plants are small, and there is not much vertical space.
The frame of the reflector should be covered with reflective material such
as aluminum foil so that all of the light is directed to the garden.
Fluorescent lights should be placed about 2-4 inches from the tops of the
plants.
   [pH:in Ed's diagram, the reflectors between the lights have a shape
    similar to this:

            *                *
               *          *
                 *      *
                  *    *
                   *  *
                   *  *
                    **

   Sort of a curving V, if you see what I mean.]

   Growers sometimes use fluorescent lights in innovative ways to supplement
the main source of the light.  Lights are sometimes placed along the sides
of the garden or in the midst of it.  One grower used light wands which he
hung vertically in the midst of the garden.  This unit provided light to the
lower parts of the plant which are often shaded.  Another grower hung a tube
horizontally at plant level between each row.  He used no reflector because
the tube shined on the plants from ever angle.  Lights can be hung at
diagonal angles to match the different plants' heights.

                     VERY HIGH OUTPUT (VHO) FLUORESCENTS

   Standard fluorescents use about 10 watts per linear foot - a 4 foot
fluorescent uses 40 watts, an 8 footer 72 watts.  VHO tubes use about three
times the electricity that standard tubes use, or about 215 watts for an 8
foot tube, and they emit about 2.5 times the light.  While they are not
quite as efficient as a standard tube, they are often more convenient to
use.  Two tubes per foot produce the equivalent electricity of 5 standard
tubes.  [pH:That's what he says.  Why one would want the tubes to produce
electricity instead of light I will never know.]  Only one tube per foot is
needed and two tubes emit a very bright light.  The banks of tubes are
eliminated.
   VHO tubes come in the same spectrums as standards.  They require
different ballasts than standards and are available at commercial lighting
companies.

                              METAL HALIDE LAMPS

   Metal halide lamps are probably the most popular lamp used for growing.
These are the same type of lamp that are used outdoors as streetlamps or to
illuminate sports events.  They emit a white light.  Metal halide lamps are
very convenient to use.  They come ready to plug in.  The complete unit
consists of a lamp (bulb), fixture (reflector) and long cord which plungs
into a remote ballast.  The fixture and lamp are lightweight and are easy to
hang.  Only one chain or rope is needed to suspend the fixture, which take
up little space, making it easy to gain access to the garden.
   In an unpublished, controlled experiment, it was observed that marijuana
plants responded better to light if the light came from a single point
source such as a metal halide, rather than from emissions from a broad area
as with fluorescents.  Plants growing under metal halides develop quickly
into strong plants.  Flowering is profuse, with heavier budding than under
fluroescents.  Lower leaf development was better too, because the light
penetrated the top leaves more.
   Metal halide lamps are hung in two configurations: veritcal and
horizontal.  The horizontal lamp focuses a higher percent of light on the
garden, but it emits 10% less light.  Most manufacturers and distributors
sell verically hanging metal halides.  However, it is worth the effort to
find a horizontal unit.
   In order for a vertical hanging metal halide lamp to deliver light to the
garden efficiently, the horizontal light that is emitting must be directed
downward or the halide must be placed in the midst of the garden.  It only
becomes practical to remove the reflector and let the horizontally directed
light radiate when the plants have grown a minimum of six feet tall.
Reflectors for vertical lamps should be at least as long as the lamp.  If a
reflector does not cover the lamp completely, some of the light will be lost
horizontally.  Many firms sell kits with reflectors which do not cover the
whole lamp.
   Reflectors can be modified using thin guage wire such as poultry wire and
aluminum foil.  A hole is cut out in the middle of the chicken wire frame so
that it fits over the wide end of the reflector.  Then it is shaped so that
it will distribute the light as evenly as possible.  Aluminum foil is placed
over the poultry wire.  (One grower made an outer frame of 1 x 2's which
held the poultry wire, metal halide, and foil).
   Metal halide lamps come in 400, 1000, and 1500 watt sizes.  The 1500 watt
lamps are not recommended because they have a much shorter life than the
other lamps.  The 400 watt lamps can easily illuminate a small garden 5 x 5
feet or smaller.  These are ideal lights for a small garden.  They are also
good to brighten up dark spots in the garden.
   In European nurseries, 400 watt horizontal units are standard.  They are
attached to the ceiling and placed at even 5 foot intervals so that light
from several lamps hits each plant.  Each lamp beam diffuses as the vertical
distance from the plants may be 6-8 feet, but no light is lost.  The beams
overlap.  No shuttle type device is required.  The same method can be used
with horizontal 1000 watt lamps and 8 foot intervals.  Vertical space should
be at least 12 feet.

                       HIGH PRESSURE SODIUM VAPOR LAMPS

   Sodium vapor lamps emit an orange or amber-looking light.  They are the
steet lamps that are commonly used these days.  These lights look peculiar
because they emit a spectrum that is heavily concentrated in the yellow,
orange, and red spectrums with only a small amount of blue.  They produce
about 15% more light than metal halides.  They use the same configuration as
metal halides: lamp, reflector, and remote ballast.
   Growers originally used single sodium vapor lamps primarily for flowering
because they thought that if the extra yellow and orange light was closer to
the sun's spectrum in the fall, when the amount of blue light reaching Earth
was limited, the red light would increase flowering or resin production.  In
another unpublished controlled experiment, a metal halide lamp and a sodium
vapor lamp were used as the only sources of light in 2 different systems.
The garden under the metal halide matured about a week faster than the
garden under the sodium vapors.  Resin content seemed about the same.  Other
growers have reported different results.  They claim that the sodium vapor
does increase THC and resin production.  Plants can be grown under sodium
vapor lights as the sole source of illumination.
   Many growers use sodium vapor lamps in conjunction with metal halides; a
typical ratio is 2 halides to 1 sodium.  Some growers use metal halides
during the growth stages but change to sodium vapor lamps during the harvest
cycle.  This is not hard to do since both lamps fit in the same reflector.
The lamps use different ballasts.
   High pressure sodium vapor lamps come in 400 and 100 watt configurations
with remote ballasts designed specifically for cultivation.  Smaller
wattages designed for outdoor illumination are available from hardware
stores.  The small wattage lamps can be used for brightening dark areas of
the garden or for hanging between the rows of plants in order to provide
bright light below the tops.

                                 ACCESSORIES

   One of the most innovative accessories for lighting is the "Solar
Shuttle" and its copies.  This device moves a metal halide or sodium vapor
lamp across a track 6 feet or longer.  Because the lamp is moving, each
plant comes directly under its field several times during the growing
period.  Instead of plants in the center receiving more light than those on
the edge, the light is more equally distributed.  This type of unit
increases the total efficiency of the garden.  Garden space can be increased
by 15-20% or the lamp can be used to give the existing garden more light.
   Other units move the lamps over an arc path.  The units take various
amounts of time to complete a journey - from 40 seconds upward.

                           ELECTRICITY AND LIGHTING

   At 110-120 volts, a 1000 watt lamp uses about 8.7 amps (watts divided by
volts equals amps).  Including a 15% margin for safety it can be figured as
10 amps.  Many household circuits are rated for 20 or 30 amps.  Running 2
lights on a twenty amp circuit taxes it to capacity and is dangerous.  If
more electricity is required than can be safely supplied on a circuit, new
wiring can be installed from the fusebox.
   All electrical equipment should be grounded.
   Some growers report that the electrical company's interest was aroused,
sometimes innocently, when their electric bill began to spurt.  After all,
each hour a lamp is on it uses about 1 kilowatt hour.