Artificial
grow rooms offer a tremendous opportunity to produce maximum
yields of selected plants at any time of the year. Although
the initial set up cost may seem high the bumper crops
you’ll produce will quickly offset the expense.
Until recent years, indoor crop
production was very restricted. Providing adequate light
was the most limiting factor in achieving a viable flowering
crop. Full spectrum fluorescent lights were used effectively
for propagation and some limited vegetative growth but proved
inadequate for fruiting and flowering.
Today, thanks to research and advanced
technology, growing plants indoors using supplemental light
has become a popular and economical way to produce a variety
of crops. Hydroponics, under lights is the preferred method of
cultivation for many growers. The needs of plants can be met
without the use of mineral soil when growing indoors.
Hydroponics provides the necessary mineral elements directly
to the plant’s roots. The mineral salts provided in
hydroponics are the exact same as those found in soil. A
mineral-based soil that comes from your garden does not work
well indoors. The bacteria that break down the organic
compounds into mineral elements that the plants use are
quickly depleted.
The easiest way to get started is to
create a floor plan. Measure the designated area and draw your
floor plan to scale. The size of your room in square feet and
cubic feet will be important factors in accurately determining
the amount of light, C02,
ventilation etc., required. The experts at your hydroponic
retail store can tell you exactly what you will need for a
particular area. A small closet garden or a full basement
set-up can be put together in the most economical way when
everything is first laid out on paper.
When deciding where to situate your
grow room, some of the most important things to consider are:
Accessibility to electricity, plumbing and ventilation.
Determine how many lights, and the wattage you will be using.
Ensure your electrical panel has enough amperage to run the
lights and all the equipment. For example a 1000 watt bulb run
from a regular 100/120 volt receptacle will require 10 amps.
The average new house has 200 amp service, more than enough to
run a small grow room. If you need more amperage you should
consider having a qualified electrician upgrade your panel.
Running you lights on a 240 volt receptacle (a household dryer
receptacle) you can optimize amps used. At 240 volts 6 x
1000 watt lamps will draw 30 amps. In order to use 240 volt
service the ballast must be retrofitted when purchased. Your
retailer will usually do this quickly at no extra charge.
Whenever you purchase any electrical appliance, for your own
safety, and your family’s if you’re growing in your home,
make sure they are CSA approved.
The walls
of your grow room should be insulated with a regular vapour
proof insulation. This will help reduce running costs and make
it easier to maintain the ideal temperature. Walls should be
as close to the growing area as is practical and covered with
a reflective material such as mylar or white plastic to
achieve maximum light reflection. Do not use tinfoil for
reflection as it creates hot spots which may burn your plants.
Mylar reflects up to 95% efficiency when it is tacked flat
against walls. Wavy or loose mylar will decrease reflective
ability. White plastic sheeting reflects 90-93% efficiency and
can be used to construct portable, waterproof walls. Lining
the back side of walls and windows with inexpensive black
plastic sheeting will ensure there is no light seepage into or
out of your grow room. If your grow room is in the basement
you may want to add an insulated sub-floor.
There are
several different garden systems used in hydroponics the most
popular being ebb and flow, (flood and drain) deep water
culture or pots with soilless mix. Whichever system you choose
the important factors to remember are good drainage,
irrigation, and availability of oxygen to the root system.
Easy access to running water and a drain will make the job of
filling and empting the reservoirs or hand watering pots much
easier. Keep growing tables elevated to a comfortable working
height with enough room to move unrestricted between each
table. A sub-floor is particularly important if growing in
pots directly on the floor as the growing medium or root zone
should be kept a constant temperature of 80 - 85º F for
optimum growth.
It is essential that your grow room be
kept clean and free of stagnant water. Starting off with
sterilized equipment and always wearing clean clothes will
help keep plants free of contamination. There are many
non-toxic antifungal sterilizing agents available. If you have
been to visit another grow room, nursery or greenhouse it is
always wise to shower and change clothes prior to entering
your room. Many insects and diseases are passed through touch
or catch a free ride on clothing. Any new plant material
should be quarantined for at least a week before introducing
it into your room. Discard any decaying plant material or used
growing medium, reservoir or tables. Remove any visible of
algae whenever possible.
You are ‘Mother Nature’ in your
indoor hydroponic grow room. You must recreate all of
nature’s fundamentals within the walls of the room you
construct. Wind, rain, sunshine, temperature fluctuations,
light, day/night cycle and nutrition are all part of the
simulated atmosphere in a grow room. These, along with oxygen
(O2), carbon
dioxide (CO2),
potential hydrogen (pH) are what are termed Growth Influencing
Factors or (GIF’s) among hydroponic enthusiasts. As in
nature, you will need to find the perfect balance for each GIF
and have all elements run in harmony. If any of the GIF’s
are missing or out of balance growth will be compromised and
entire crops may be lost. The weakest link in the chain
determines the outcome of your best efforts.
To understand what GIF’s are to a
plant indoors, is to understand basic plant physiology. The
most important growth influencing factor (GIF) is light.
Scientific breakthroughs have shed bright light on indoor
horticulture. The metal halide lamps on the market today have
all but replaced fluorescent lamps for growing purposes,
providing a spectrum and intensity as close as possible to the
natural sunlight.
Lights range in size from 175 watt to
1000 watt. A 1000 watt bulb will cover 16 to 25 square feet
depending on the desired light intensity. It is recommended
that lights be used with a reflector to maximize the full use
of the bulb’s lumen output. A reflector will make sure all
light is directed downward toward your plant and not wasted
throughout the room. The style and size of the reflector you
choose will depend on the size of the lamp, desired light
intensity and area of coverage. The most efficient way to use
any high intensity light is with a light mover. Lights can be
placed closer to the crop, stems will be stronger and plant
growth can increase up to 40%. There are circular light movers
that are capable of moving up to three lights at a time or
linear light movers on the market today.
Seedlings respond to continuous light.
Place seedlings in a humidity tent under a fluorescent bulb 24
hours a day. Once the first true leaves appear remove tent and
cut light time to 18 hours. To propagate stem cuttings place
them under a 6" humidity dome and provide 18 hours
of fluorescent light. Use a rooting hormone to ensure good
root development.
For
optimum growth at maturity supply up to 18 hours of light
followed by a six hour period of uninterrupted and
complete darkness for respiration to transpire. Respiration
must occur in every living cell if life is to be maintained
and to allow a plant the ability to use energy and thus grow
and produce flowers and fruit. Respiration occurs mainly
during the lights off cycle. Light requirements will vary with
growth stages and different plants.
Timers are
the easiest way to automate your grow room. Plants will
respond to an accurate day/night schedule and watering
routine. With a timer you can establish a day/night schedule
that suits your schedule; it is not necessary to conform to
the outside environmental dark/light hours. (Plug in fans, air
pumps and drip irrigation pumps into the same timer as the
light)
Nutrition
is the second most important GIF and will be an integral part
of your hydroponic gardening success. Plants grow faster in
hydroponics because their food supply is constantly available.
In the basic hydroponic system plants are fed by passing the
nutrients over the roots or flooding around the root area at
regular intervals, and then later draining off. In a soilless
mix plants can be hand watered from the top as you would with
a regular soil container.
Electrical
conductivity (EC), measured in milliMhos, is the measure of
electrical conductance of the total dissolved solutes
(minerals) in the solution. The optimum EC range varies among
different plants. While EC measures the total dissolved
minerals in a solution it does not identify the amounts of
specific elements present. Therefore, it is easier to achieve
the ideal EC using premixed two-part hydroponic nutrient
formulations than attempting to create your own formula using
individual components. It is necessary to change the nutrient
formula between the vegetative and flowering stages to ensure
that plants receive the specific elements required at the
different stages of growth. EC testers are the most accurate
way of monitoring and maintaining a desirable nutrient level
in your reservoir.
pH is the
measure of alkalinity or acidity of the nutrient solution
and is an important consideration in hydroponics. The
ideal pH level for most plants is between 5.5 and 6.5. If the
pH is not within this range plants will not be able to absorb
nutrients at the maximum level. pH should be tested on a
daily basis using an inexpensive test solution or a pH meter.
Even seemingly small pH fluctuations can have a big impact on
plants ability to utilize nutrients. The pH is easily adjusted
with a pH Up or pH Down solution to obtain the desired level.
pH can be tested using a simple litmus paper or a pH meter may
be used for exact digital readings.
Photosynthesis
is the manufacture of sugar from two simple raw materials -
carbon dioxide and water - in the presence of chlorophyll with
sunlight
(or
artificial light) as the source of energy. Carbon dioxide (CO2)
is vital to the plants survival. The normal atmospheric level
is about 340 parts per million (ppm). Research has shown that
plants are able to use more CO2
than is available in the atmosphere (up to 1500 ppm) to grow
larger and faster. CO2 enrichment in your grow room has the
potential to dramatically increase your yield with little
cost. A CO2
injector should be used in conjunction with an exhaust fan to
ensure all CO2
is exhausted between cycles. The injector should be installed
above the lights because CO2
is heavier than air and will float down through the plants,
resulting in maximum intake.
It is
absolutely essential to have good ventilation with an incoming
supply of fresh air (oxygen) as plants will soon consume all
the CO2 in an
enclosed environment. Plants could not complete
respiration or utilize the food produced by photosynthesis
unless they have a good supply of oxygen. An oscillating fan
in the room will simulate the wind reducing ambient leaf
temperature, restoring CO2
to the leaf zone and strengthening the stems. It will also
make sure there is good distribution of fresh air throughout
the room and help control humidity levels.
Atmospheric
temperature must be monitored and controlled within the room.
As in the outdoors there needs to be an air temperature
differential between the plant’s perceived daytime and
nighttime. When there is light the plant considers it daytime
and the temperature should be maintained around 18 - 25oC
and nighttime is 12 - 18oC. (This may vary slightly
for different plants). An independent thermostat should be
placed among your plants to ensure temperature regulation.
All these
things are controlled by you, the grower. With everything
taken into consideration your grow room should reward you with
an easily maintained system and produce unending yields.