Marijuana lighting and you

Light
     Without light,  the plants cannot grow.  In the countries in  which marijuana grows best,  the sun is the source of light.  The
amount  of  light and the length of the growing season  in  these  countries  results in huge tree-like plants.   In most  parts  of
North America,  however,  the sun is not generally intense enough  for  long  enough periods of time to produce the  same  size  and  quality of plants that grow with ease in Latin America and  other  tropical  countries.   The answer to the problem of lack of  sun,  especially in the winter months, shortness of the growing season,  and other problems is to grow indoor under simulated  conditions.   The rule of thumb seems to be the more light, the better.  In one  experiment we know of, eight eight-foot VHO Gro-Lux fixtures were  used over eight plants.   The plants grew at an astonishing rate.   The lights had to be raised every day.   There are many types  of  artificial  light  and all of them do different  things  to  your  plants.   The  common incandescent light bulb emits some  of  the  frequencies of light the plant can use,  but it also emits a high  percentage  of far red and infra-red light which cause the  plant  to concentrate its growth on the stem.  This results in the plant  stretching  toward  the light bulb until it becomes so  tall  and  spindly  that  it just weakly topples over.   There  are  several  brands  of bulb type.   One is the incandescent plant spot  light  which emits higher amounts of red and blue light than the  common  light bulb.   It is an improvement,  but has it drawbacks.  it is  hot,  for  example,  and  cannot be placed close to  the  plants.   Consequently,  the  plant has to stretch upwards again and is  in  danger of becoming elongated and falling over.   The red bands of  light  seem  to encourage stem growth which is not  desirable  in  growing marijuana.   the idea is to encourage foliage growth  for  obvious  reasons.   Gro-Lux lights are probably the  most  common  flourescent plant lights.  In our experience with them, they have
proven themselves to be extremely effective.   They range in size  from one to eight feet in length so you can set up a growing room  in  a  closet or a warehouse.   There are two  types  of  Gro-Lux  lights:  The standard and the wide spectrum.  They can be used in  conjunction with on another, but the wide spectrum lights are not  sufficient on their own.   The wide spectrum lights were designed  as a supplementary light source and are cheaper than the standard  lights.  Wide spectrum lights emit the same bands of light as the  standard  but the standard emit higher concentrations of red  and  blue  bands  that the plants need to  grow.   The  wide  spectrum  lights also emit infra-red, the effect of which on stem growth we  have already discussed.   If you are planning to grow on a  large  scale,   you  might  be  interested  to  know  that  the  regular  flourescent  lamps  and  fixtures,  the type  that  are  used  in  commercial lighting, work well when used along with standard Gro- Lux lights.   These commercial lights are called cool whites, and  are  the  cheapest of the flourescent lights we  have  mentioned.   They  emit  as much blue light as the Gro-Lux standards  and  the  blue light is what the plants use in foliage growth.
     Now we come to the question of intensity.  Both the standard  and  wide  spectrum lamps come  in  three  intensities:   regular  output,  high output,  and very high output.  You can grow a nice  crop  of  plants under the regular output lamps and  probably  be  quite satisfied with our results.  The difference in using the HO  or  VHO lamps is the time it takes to grow a crop.   Under a  VHO  lamp,  the  plants grow at a rate that is about three  times  the  rate  at which they grow under the standard lamps.   People  have  been  known to get a plant that is four feet tall in  two  months  under one of these lights.  Under the VHO lights, one may have to  raise the lights every day which means a growth rate of ate least  two  inches a day.   The only drawback is the expense of the  VHO  lamps and fixtures.   The VHO lamps and fixtures are almost twice  the price of the standard.  If you are interested in our opinion,  they are well worth it.   Now that you have your lights  up,  you  might be curious about the amount of light to give you plants per  day.  The maturation date of your plants is dependent on how much  light they receive per day.   The longer the dark period per day,  the sooner the plant will bloom.   Generally speaking,  the  less  dark  per  day  the better during the first  six  months  of  the  plant's life.   The older the plant is before it blooms and  goes  to  seed,  the  better the grass will be.   After  the  plant  is  allowed  to  bloom,  its  metabolic rate is slowed  so  that  the  plant's  quality does not increase with the age at the same  rate  it did before it bloomed.   The idea,  then,  is to let the plant  get  as old as possible before allowing it to mature so that  the  potency will be a high as possible at the time of  harvest.   One  relatively  sure way to keep your plants from blooming until  you  are  ready  for  them is to leave the lights  on  all  the  time.   Occasionally  a plant will go ahead and bloom anyway,  but it  is  the  exception rather than the rule.   If your plants receive  12  hours  of  light per day they will probably mature in  2  to  2.5  months.  If they get 16 hours of light per day they will probably  be blooming in 3.5 to 4 months.   With 18 hours of light per day,  they will flower in 4.5 to 5 months.  Its a good idea to put your  lights  on  a timer to ensure that the amount of  light  received  each day remains constant.   A "vacation" timer, normally used to  make it look like you are home while you are away,  works  nicely  and can be found at most hardware or discount stores.   
           Energy Emissions In Arbitrary Color Bands
                    40 Watt Flourescent Lamps
             In Watts and Percent of Total Emissions
                                                   Daylight          Cool White         Gro-Lux        GroLux WS
Light Type               Band           Watts   %            Watt   %          Watt   %          Watt   %
~~~~~~~~~~~~ ~~~~~~~ ~~~~~~~~~~~  ~~~~~~~~~~  ~~~~~~~~~~  ~~~~~~~~~~
Ultra-Violet             -380        0.186  2.15        0.16  1.68         0.10  1.42         0.27  3.16
Violet                   380-430     0.832  9.60        0.72  7.57         0.70  9.67         1.07 12.48
Blue                     430-490     2.418 27.91       1.98 20.78        1.96 27.07        1.22 14.29
Green                  490-560     2.372 27.38        2.35 24.67        1.02 14.02        1.24 14.49
Yellow                560-590      1.259 14.53        1.74 18.27        0.10  1.42         0.83  9.77
Orange               590-630      1.144 13.21       1.69 17.75         0.44  6.05          1.36 15.93
Red                    630-700      0.452  6.22        0.81  8.47          2.86 39.55         1.86 21.78
Far Red              700-780      0.130  1.53        0.07  0.81          0.06  0.80           0.69  8.10
==================== ===========  ==========  ==========  ==========
Total                                      8.890 100.0          9.52 100.0        7.24 100.0        8.54 100.0