Grow light
Dual spectrum compact fluorescent grow light. Actual length is about 40cm.A grow
light is an electric lamp designed to promote plant growth by emitting an
electromagnetic spectrum appropriate for photosynthesis. The emitted light
spectrum is similar to that from the sun, allowing indoor growth with outdoor
conditions. Natural daylight has a high color temperature (approx. 6000°K) and
appears bluish. Through the use of the color rendering index, it is possible
compare how much the lamp matches the natural color of regular sunlight.
Contents grow lights
1 Light spectrums used
2 Types & set-ups
2.1 Incandescent grow lights
2.2 Fluorescent grow lights
2.3 Metal-Halide (MH) HID grow lamps
2.4 High-pressure sodium lamps
2.5 Combination HPS/MH lamps
2.6 Switchable, convertible & two-way lamps
2.7 LED grow lamps
3 Use
4 Light requirements of plants
grow lights Light spectrums used
The light spectrums of different grow lampsDifferent light spectrums are used
for the different stages of plant growth. The initial vegetative stage requires
blue spectrum of light, whereas the later 'flowering' stage is usually done with
red/orange spectrums. The lights can be bought by spectrum colour specifically,
or some companies such as Sylvania Grolux produce a full spectrum bulb which
caters for all stages of growth.
The light is usually used in conjunction with a reflector, to control and
intensify the light emissions, and will include an electrical ballast to control
the flow of current flowing to the light. This is required because of the high
intensity of the light that is necessary to produce something akin to sunlight.
grow lights Types & set-ups
Lamp types used as grow lights include incandescents, fluorescent lamps,
high-intensity discharge lamps, and LEDs.
Today, the most widely used lights for professional indoor flower and vegetable
growing are HPS/SON (high pressure sodium) and MH (metal halide). These are
types of HID or high-intensity discharge lamps. MH is used for vegetative phase
of growth, as it encourages short internodes (distance between sets of leaves),
and inhibits cell elongation, creating a shorter, stockier plant. Unlike high
pressure sodium lamps, metal halide lamps also produce ultraviolet radiation,
which may play a role in increasing the amount of THC produced by the plant.
High pressure sodium lamps trigger a greater flowering response in the plant and
are thus used for the for the second (or reproductive) phase of the growth, or
they are used by those people who only wish to purchase 1 single lamp. [1] If
high pressure sodium lamps are used for the vegetative phase, plants will
usually grow slightly more quickly, but will also have longer internodes, and
may be taller. [2]
grow lights Incandescent grow lights
Incandescent grow lights have a red-yellowish tone and low color temperature
(approx. 2700°K). They are solely used to highlight indoor plant groupings and
not as a true plant 'growing' light (aldough they may be labeled as such).
Incandescent growing lamps have an average life span of 750 hours.
grow lights Fluorescent grow lights
Today, (HID) lights are available in any desired color temperature in the range
from 2800°K to 6000°K. Standard fluorescents are usually used for growing
vegetables (as leaf lettuce, spinach, and herbs) or for starting seedlings to
get a jump start on spring plantings. Standard fluorescents produce twice as
many lumens per watt of energy consumed (compared to incandescents) and have an
average usable life span of up to 20,000 hours. This is 25 times as long as an
incandescent. Cool white fluorescent lamps are sometimes used as grow lamps.
These offer slightly lower performance, a white light, and lower purchase cost.
High Output fluorescents produce twice as much light as standard fluorescent
lamps. A HO fluorescent fixture has a very thin profile, making it extremely
useful in vertically limited areas. High Output Fluorescents produce about 5,000
lumens per 54 watt bulb and are available in warm (3000°K) and cool (6500°K)
versions. Usable life span for High Output fluorescent lamps is about 10,000
hours.
Compact fluorescents are smaller versions of fluorescent lamps and are used for
propagation, aswell as for growing larger plants. Compact fluorescents work in
specially designed reflectors that efficiently direct light to the plants, much
like the HID lamps below. Compact fluorescent bulbs are also available in warm
(3000K) and cool (6500K) versions. Usable life span for compact fluorescent grow
lamps is about 10,000 hours.
High Output Fluorescent/HID hybrids combine cool burning with the penetration of
high intensity discharge technology. Primary advantages to these fixtures is
their blend of light colors and broad even coverage.
grow lights Metal-Halide (MH) HID grow lamps
Metal halide HID lamps deliver a white light in the range of 2700 to 5500°
Kelvin with a color rendering index of 65-75. As such, plants growing under most
metal halide lamps appear almost identical to those growing outside. They are
used where color rendering is important such as stadiums, malls, manufacturing
plants, and supermarkets. Metal halide lamps are five times more efficient than
incandescent lamps and last up to 25 times longer, with a usable lifespan
between 10,000 and 20,000 hours, depending on the wattage. Horticultural metal
halide lamps have an enhanced red spectrum, which is added for increased
fruiting and flowering.
grow lights High-pressure sodium lamps
high pressure sodium lamps yield yellow lighting (2200K) and have a very poor
color rendering index of 22. They are used used for the for the second (or
reproductive) phase of the growth. If high pressure sodium lamps are used for
the vegetative phase, plants will usually grow slightly more quickly, but will
also have longer internodes, and may be taller.They are used in less color
critical applications such as parking lots, street lights and for supplemental
greenhouse lighting. The benefit of high pressure sodium lamps to the
horticultural industry is their ability to enhance the fruiting and flowering
process in plants. Orange/red spectrum HPS produces is the spectrum plants use
in their reproductive processes, which generally produces larger harvests of
higher quality fruits or flowers.Plants grown under high pressure sodium however
yields taller and leggier plants with a longer internodal length than plants
grown under the bluer light of metal halide. Also, the plants grown under these
lamps do not appear very healthy (aldough they usually are).This is due to the
poor color rendering of high pressure sodium, which makes the plants look pale,
washed out or nitrogen starved. Benefits to high pressure sodium lighting are
their incredibly long usable bulb life (up to two years in many cases); and
unparralled efficiency at six times more light output per watt of energy
consumed than a standard incandescent grow lamp. Due to their high efficiency
and the fact that plants grown in greenhouses get all the blue light they need
naturally, these lamps are the preferred supplemental greenhouse lights.
grow lights Combination HPS/MH lamps
Combination HPS/MH lamps combine a metal halide bulb and a high pressure sodium
bulb in the same reflector, either with a single integrated ballast assembly or
two separate ballast assemblies. The combination of blue metal halide light and
red high pressure sodium light creates an ideal spectral blend and extremely
high outputs.
grow lights Switchable, convertible & two-way lamps
Switchable, Two-Way and convertible lamps are used to burn either a metal halide
bulb or an equivalent wattage high pressure sodium bulb in the same fixture, but
not at the same time. These fixtures are used for propagating and vegetatively
growing plants under the metal halide, then switching to a high pressure sodium
bulb for the fruiting or flowering stage of plant growth. To change between the
lamps, only the bulb needs changing and a switch needs to be set to the
appropriate setting.
grow lights LED grow lamps
LED panel light source used in an experiment on plant growth by NASA. Pictured
plant is a potato plant.Recent advancements in LEDs have allowed for the
production of relatively cheap, bright and long lasting grow lights that emit
only the colors of light required for plant growth. These lights are attractive
to indoor-growers since they do not consume as much power, do not require
ballasts, and produce a fraction of the heat of HID lamps. The lamps consist of
arrays of many wide-spectrum red and a few narrow-spectrum blue LEDs of specific
wavelengths. Although LED grow lights have shown promise through plant research
by NASA and many universities, it is unknown whether the results are applicable
to the cultivation of all plant-species, as their luminous efficiency is much
lower.
grow lights Use
Grow lights are most used for indoor gardening, plant propogation and food
production, including indoor hydroponics and aquatic plants. Aldough most grow
lights are thus used on a industrial level, some small-scale/domestic usage of
these lamps has too ben found.
According to the inverse square law, the intensity of light radiating from a
point source (in this case a bulb) is inversely proportional to the square of
the distance from the source. So if an object is twice as far away, it receives
only 1/4 the light. This is a serious hurdle for indoor growers, and many
techniques are employed to use light as efficiently as possible. Reflectors are
thus often used in the lamps to maximize light efficiency. Plants or lights are
moved as close together as possible so that they receive equal lighting and that
all light coming from the lamps wind up on the plants (rather than partly
besides it). Often, the distance between lamp and plant is in the range of 24
inches (with incandescent lamps), up to 4 inches (with other lamps as compact,
large and high-output fluorescent lamps)[3]. Some marijuana cultivators cover
the walls of their grow-room with some type of reflective material, or
alternatively, white paint to maximise efficiency.
A commonly used covering is 6 millimeter (150 µm) PVC plastic sheeting that is
white on one side and black on the other. The plastic is installed with the
white side facing in to the room to reflect light, and the black facing the
wall, to reduce fungus and mold growth. Another common covering is flat white
paint, with a high titanium dioxide content to maximize reflectivity. Mylar
sheeting is also sometimes used, along with Astrofoil (which also reflects
heat), and Foylon (a foil-laminated, reinforced fabric).
grow lights Light requirements of plants
To determine the appropriate lighting (and the lamp to be best used), the
specific needs of the plant need to be determined. To arrange optimum lighting,
the lighting present in the plant's natural environment need to be imitated.
Offcourse, the bigger the plant gets the more light it requires; if there is not
enough light, a plant will not grow, regardless of other conditions. [4]
For example vegetables grow best in full sunlight, which means in practice that
as much light as possible must be supplied to grow vegetables indoors
(fluorescent lamps, or MH-lamps are thus preferred). Foliage plants (eg
Philodendron) grow in full shade and can therefore grow normally with relatively
little artificial light (thus for the latter, regular incandescents may already
suffice).
In addition, plants also require both dark and light ("photo"-) periods. [5] As
such, lights need to be timed to switch them on and off at set intervals. The
optimum photo/dark-periods is specific depending on each plant (some prefer long
days and short nights an others preferring the opposite, or something in
between)
For indoor gardening one of the most important topics is light density, measured
in lux. Light density is the amount of light incident on a surface. One lux
equals one lumen (unit) of light falling on an area of one square meter. A
brightly lit office would be illuminated at about 400 lux. In Imperial
(pounds-feet) terms, a foot-candle, or the intensity of a standard candle on an
area of 1 square foot, is about 10.76 lux.
grow lights References
^ Cannabis Growing Guide Part 2 - Grow lamps
^ Lights - High Pressure Sodium AND Metal Halide
^ Grow lights and specing between plants
^ Determining appropriate lighting
^ Plants requiring dark and light periods
grow lights See also
Chlorophyll
Indoor plant cultivation
This article is about methods of cultivating plants indoors, growing the them in
a soil-like medium and adding fertilizer when the plants are given water.
Cultivating plants indoors can also be done trough the use of hydroponics;
however, this method is somewhat less common [1] [2] Cultivating plants indoors
is more complicated and expensive than growing outdoors, but it allows the
cultivator complete control over the growing environment. Plants grown outdoors
(eg cannabis) can be just as potent as its indoor counterpart if tended to
properly.
Contents grow lights
1 Basics
1.1 Applying light
1.2 Arranging the right atmosphere
2 Phases of growth
2.1 Germination
2.2 Seedling phase
2.3 Vegetative phase
2.3.1 Topping
2.3.2 Pinching
2.3.3 LSTing
2.4 Reproductive/Flowering phase
grow lights Basics
To grow plants indoors, a growing medium (eg soil or growing substrate), water,
fertiliser, appropriate light and atmosphere need to be applied to the plant.
grow lights Applying light
To determine the appropriate lighting (and the lamp to be best used), the
specific needs of the plant need to be determined. To arrange optimum lighting,
the lighting present in the plant's natural environment need to be imitated. [3]
For example vegetables grow best in full sunlight, which means in practice that
as much light as possible must be supplied to grow vegetables indoors
(fluorescent lamps, or MH-lamps are thus preferred). Foliage plants (eg
Philodendron) grow in full shade and can therefore grow normally with relatively
little artificial light (thus for the latter, regular incandescents may already
suffice).
In addition, plants also require both dark and light ("photo"-) periods. [4] As
such, lights need to be timed to switch them on and off at set intervals. The
optimum photo/dark-periods is specific depending on each plant (some prefer long
days and short nights an others preferring the opposite, or something in
between)
Most plants will grow under most light spectra, yet always prefer a full
spectrum light. A test done by Ed Rosenthal[citation needed] found that when a
room was set up using both high pressure sodium (HPS) and metal halide (MH)
lamps the plants in between the two lights did better than those under MH alone
but not as well as those under HPS. However, Cannabis can be grown successfully
under both types of light. MH is used for vegetative phase of growth, as it
encourages short internodes (distance between sets of leaves), and inhibits cell
elongation, creating a shorter, stockier plant. Unlike high pressure sodium
lamps, metal halide lamps also produce ultraviolet radiation, which may play a
role in increasing the amount of THC produced by the plant. High pressure sodium
lamps trigger a greater flowering response in the plant and are thus used for
the for the second (or reproductive) phase of the growth, or they are used by
those people who only wish to purchase 1 single lamp. [5] If high pressure
sodium lamps are used for the vegetative phase, plants will usually grow
slightly more quickly, but will also have longer internodes, and may be taller.
[6]
Recent advancements in LEDs have allowed for the production of relatively cheap,
bright and long lasting grow lights that emit only the colors of light required
for plant growth. These lights are attractive to indoor-growers since they do
not consume as much power, do not require ballasts, and produce a fraction of
the heat of HID lamps. The lamps consist of arrays of many wide-spectrum red and
a few narrow-spectrum blue LEDs of specific wavelengths. Although LED grow
lights have shown promise through plant research by NASA and many universities,
it is unknown whether the results are applicable to Cannabis cultivation, as
their luminous efficiency is much lower.
LED panel light source used in an experiment on plant growth by NASA. Pictured
plant is a potato plant.According to the inverse square law, the intensity of
light radiating from a point source (in this case a bulb) is inversely
proportional to the square of the distance from the source. So if an object is
twice as far away, it receives only 1/4 the light. This is a serious hurdle for
indoor marijuana growers, and many techniques are employed to use light as
efficiently as possible.
Reflectors are often used in the lamps to maximize light efficiency. Plants or
lights are moved as close together as possible so that they receive equal
lighting and that all light coming from the lamps wind up on the plants (rather
than partly besides it). Often, the distance between lamp and plant is in the
range of 24 inches (with incandescent lamps), up to 4 inches (with other lamps
as compact, large and high-output fluorescent lamps)[7]. Some marijuana
cultivators cover the walls of their grow-room with some type of reflective
material, or alternatively, white paint to maximise efficiency.
The most commonly used covering is 6 millimeter (150 µm) PVC plastic sheeting
that is white on one side and black on the other. The plastic is installed with
the white side facing in to the room to reflect light, and the black facing the
wall, to reduce fungus and mold growth. Another common covering is flat white
paint, with a high titanium dioxide content to maximize reflectivity. Mylar
sheeting is also sometimes used, along with Astrofoil (which also reflects
heat), and Foylon (a foil-laminated, reinforced fabric).
grow lights Arranging the right atmosphere
When growing indoors, the cultivator should maintain as close to an ideal
atmosphere inside the grow-room as possible. The air temperature must be
maintained within an ideal range, typically with deviations no larger than 15
deg.F. with a cooler night and warmer day, and if adequate levels of CO2 are
maintained in order for the plants will grow most efficiently. It is also
important to promote vigorous air circulation within the grow room, which is
usually accomplished by mounting one or more oscillating fans in the room,
depending on its size. Using an air extraction fan, sometimes with a smaller
fan, ensures air exchange.
Assuming adequate light and nutrients are available to plants, the limiting
factor in plant growth is the level of carbon dioxide (CO2). Plants grown with
supplemental carbon dioxide will grow more quickly, have larger stomata, and can
utilize more light. Ways of increasing carbon dioxide levels in the grow-room
include: bottled carbon dioxide, carbon dioxide generators, a milk jug and yeast
solution (in which yeast grows in a container hereby emitting CO2), a baking
soda and vinegar mixture in a container, or dry ice.[8]
Certain plants (eg most strains of cannabis]] emit a distinctive odor during
their reproductive phase. This presents difficulties to those who are
cultivating in places where it is illegal. The most common way of eliminating
odor is by pulling odorous air through a carbon filter. Many cultivators simply
attach a large carbon filter to their air extraction system, thereby filtering
any smell before the air is expelled from the grow-room. Another way of
eliminating odor is by installing an ozone generator in the extraction ducting.
The air is forced past the ozone generator by the extraction fan, and the
odorous air is neutralized as it mixes with the ozone; however the cultivator
must ensure that the air is thoroughly mixed before it is expelled outside, lest
some odor escape. Care must be taken to prevent excessive ozone concentrations
in the garden itself, or where it might be inhaled by the grower or his/her
family. Ozone itself has a distinctive smell and is harmful to living things,
although the molecule breaks down quickly (20 minutes to an hour) in atmospheric
conditions.
grow lights Phases of growth
grow lights Germination
Seeds may be germinated by soaking in paper towels, or a cup of water at room
temperature, or in wet Jiffy pellets. Regardless of which method used distilled
water is always employed as it has the proper pH. Jiffy pellets are often used
as a growth medium as they make it unnecessary to transplanting the fragile
seedlings. This, as the saturated pellets with their seedlings can be planted
directly in the intended growing medium with a minimum of trouble and effort.
When germinating, the seeds must be kept in a dark, moist and warm environment.
Germination occurs once water has soaked into the seed and initiates metabolic
processes. The seed soon splits and the embryonic root emerges and begins
growing downwards due to gravity. Once anchored the root will push the entire
seed out above the soil where the seed shell will be lost to expose two circular
embryonic leaves (or cotyledons).
This marks the beginning of the seedling stage.
grow lights Seedling phase
The seedling stage of growth begins when the seed breaks the soil and exposes
its round “seed leafs” or cotyledon. This is the most fragile time during the
entire life cycle of the cannabis plant. It is important to keep a constant
atmosphere with a high humidity level and medium to high light intensity. Most
growers use compact fluorescents or T5 fluorescents during this stage as they
give off little heat. HPS and MH lights give off large amounts of radiant heat
and increase the rate of transpiration in the plant. Seedlings have small root
systems and can dry out very quickly, thus keeping soil moist is important at
this stage. During the seedling stage fertilizers are not necessary and should
not be given to the plant. The plant often sexes during this stage but will not
preflower.
grow lights Vegetative phase
When the plant possesses 4 sets of true leafs and the 5th is barely visible in
the center of the growth tip, the plant has entered the vegetative phase of
growth. During the vegetative phase of growth, the plant directs its energy
resources primarily to the growth of leaves, stems, and roots. A strong root
system is imperative, as it is required for strong floral development. A plant
needs 1 or 2 months to mature before blooming. The plant is ready when it has
revealed its sex. The males are then culled when they are identified, because
they don't produce buds or flowers. If males are allowed to pollinate the
females their potency will be greatly reduced, as energy that would have been
used to make large, potent buds instead goes to making seeds.
During the vegetative phase of growth, cultivators generally employ an 18 to 24
hour photoperiod, as the plants grow more quickly if they receive more light,
although a warmer and cooler period are required for optimal health. While no
dark period is required, there is debate among cultivators as to whether a dark
period is beneficial, and many continue to employ a dark period.
Marijuana cultivators employ fertilizers high in nitrogen and potassium during
this stage, as well as a complete micronutrient fertilizer. The strength of the
fertilizer is gradually increased as the plants grow and become more hardy.
The modification of a plant's growth habit is called training. Indoor
cultivators employ many training techniques in order to encourage shorter plants
and more dense canopy growth. For example, unless the crop is too large to be
extensively pruned, cultivators will remove adventitious growth shoots, often
called suckers, that are near the bottom of the plant and/or receive little
light and will produce poor quality buds.
Many cultivators also employ other techniques:
grow lights Topping
is done by removing the top of the apical meristem (dominant central stem),
called the apex or terminal bud, in order to transfer apical dominance (the
tendency for the apex to grow more rapidly than the rest of the plant) to the
shoots emanating from the two nodes immediately beneath the pruning cut. This
process can be repeated on one or both of the two new meristems, when they
become apically dominant, with the same results. This process can actually be
repeated almost infinitely, but over-diffusion of apical dominance will produce
smaller, lower quality buds, so it is usually done no more than a few times.
Topping also causes more rapid growth of all of the branches below the cut while
the plant heals.
grow lights Pinching
is similar to topping in that it causes the lower branches to grow more rapidly,
but the apical meristem will maintain apical dominance, which is especially
useful if the plant has already been topped. Pinching is performed by firmly
pinching the apical meristem(s) so as to substantially damage vascular and
structural cells but without totally breaking the stem. This will cause the
lower limbs to grow more rapidly while the pinched tissue heals, after which
time the stem will resume apical dominance.
grow lights LSTing
LST stands for Low Stress Training. This technique involves bending and tying
the plants branches to manipulate the plant into a more preferred growth shape.
This method of training works very well for indoor growers who need to
illuminate their plants using overhead lights. Since light intensity greatly
diminishes with increased distance (Inverse-square law) LSTing can be used to
keep all growth tips (meristem) at the same distance from the light and can
achieve optimal light exposure. LSTing is often used in conjunction with
topping, since topping increases axial growth (side shoots), topping is often
done a few weeks before beginning LSTing. LSTing works by changing the
distribution of hormones, more specifically Auxins, in the plant.
grow lights Reproductive/Flowering phase
Plants as cannabis are induced into flowering by decreasing its photoperiod to
at least 10 hours of darkness per day. Traditionally most growers change their
plants lighting cycle to 12 hours on and 12 hours off. This change in
photoperiod mimics the plant's natural outdoor cycle; with up to 18 hours of
light per day in the summer and down to less than 12 hours of light come fall
and winter. [9]
While the flowering hormone in the most plants (including cannabis) is present
during all phases of growth, it is inhibited by exposure to light. To induce
flowering, the plant must be subject to at least 8 hours of darkness per day;
this number is very strain-specific and most growers flower with 12 hours of
darkness to be safe. The flowering hormone is very quickly inhibited, taking
less than two minutes of exposure.
Flowering generally lasts from 45 to 90 days indoors. If growing outdoors it may
take somewhat longer, depending on the natural onset of the colder seasons. The
flowering length is mainly genetically determined with some pure Indica strains
flowering in as low as 45 days, while sativa strains can take up to 4 months to
finish and the harvest yields significantly less. This is the main reason Indica
strains are usually grown indoors.
Some plants, specifically members of the subspecies Ruderalis, will begin the
flowering cycle without a significant reduction in their photoperiod; this is
called autoflowering, and it is because these strains originate near the equator
which does not have the threshold darkness levels in fall.
Flowers from certain plants (eg cannabis) are called Calyx, and are with
cannabis the most prized part of the plant. In late flowering the calyx are
easily visible to the naked eye. Calyx development begins approximately 1-2
weeks after the photoperiod is reduced. In the first weeks of flowering a plant
usually doubles in size and can triple. Calyx development ends around 5 weeks
into flowering and is proceeded by a period of Calyx “swelling”. During this
time the buds greatly increase in weight and size.
grow lights Increasing popularity
Indoor growing has become increasingly common over the past decade, in part due
to increased availability of equipment, seeds and instructions on how to
cultivate. So-called grow-ops (growing operations, often located in grow houses)
are seen by many marijuana enthusiasts as a much cheaper way in which to gain a
steady, higher-quality supply of cannabis. On a larger scale they have proven a
viable commercial venture, with some law enforcement agencies finding grow-ops
large enough to yield several kilograms of marijuana. More expansive grow-ops,
however, are generally more susceptible to detection than smaller operations.
Since individual grow light power generally ranges from 250 watts to in excess
of 1000 watts and remain lit for a long time each day, differences in utility
bill costs are a significant security issue. It is not uncommon for power
companies to work with law enforcement if they witness significant increases in
power usage relative to a household's previous electricity costs. Employing
energy saving methods is a common way to alleviate this, for instance; switching
off light bulbs when leaving rooms, purchasing energy efficient appliances,
using TVs or computers less, buying lower power light bulbs and so forth.
Some strains, especially cultivars of Cannabis sativa subsp. indica, can give
off strong odors as they grow, resulting in detection. Growers frequently use
carbon scrubbers in conjunction with ventilation in order to control odors. This
typically involves forcing air from the grow room through a device containing
activated carbon, before being vented outdoors. Others use an ozone generator.
Ozone reacts with odor molecules in the air, permanently eliminating them.
However, ozone can build up to levels that may be hazardous both for the grower
and the plant. As a last resort, strong air fresheners are used to control
smells as well as keeping windows firmly shut. This is a risky method, as the
smell of air fresheners may often arouse suspicion by police officers. Checking
outside to see if any smells are emanating from indoors is often a necessary
precaution, as many growers become acclimated to the smell, and fail to realize
just how pervasive the odor may be. Many store plants in more isolated areas
such as a basement or attic to prevent smell detection. Another less common
solution is to simply grow a strain which possesses a weaker odor.
Storing plants[1] and lights away from windows and areas which may be seen by
visitors is also a common practice, as is keeping the entire grow op in an attic
or basement. Some growers, finding this impractical, may cover their windows
with light-resistant materials. This can solve the problem of escaping bright
light but may arouse suspicion amongst neighbours and local residents.
Many cultivators face detection by fire. Fires normally originate from faulty
electrical equipment or wiring. Shoddy fixtures and sockets, improperly grounded
equipment, and faulty circuit breakers are some of the most prevalent causes.
Due to the large amount of electricity needed for large-scale cultivation, old
or damaged wiring is prone to melt and short. Some commercial growers resort to
power theft in order to hide electricity usage and many do not take precautions
to ensure that their connections are safe. Many growers adapt light cycles so
that the lights are on when they are home and off when they are away.
Another fire hazard is plants making contact with hot HID bulbs. Growers using
fluorescent bulbs with reasonable air circulation do not have this problem.
Word of mouth can of course be as much a threat to growers as any of the above
issues. Often, a few sentences of conversation overheard can result in a tip-off
and thus speedy detection. It is for this reason many growers are reticent about
their cultivation.