Best lights for growing marijuana indoors?
Since there is no sun in your closet you will have to provide a
sun loving plant like marijuana with a lot of artificial light.
There are three options available to the grower: fluorescent lights
are cheap, efficient, and don't put out much heat. Metal halide, or
MH bulbs, are more expensive but put out much more light than
fluorescents. They also put out more heat so ventilation is needed.
MH bulbs also require a separate ballast in order to work. High
Pressure Sodium lamps, or HPS, put out as much light as MH lamps
but with a little less heat. Ventilation and a separate ballast are
also required. Fluorescent lights Fluorescent lights are the
cheapest light to use. They run at about $2 a tube. They produce
little heat so ventilation may not be needed unless the space is
very small. The light spectrum put out by these lights is suitable
for all stages of growing. Because fluorescents disperse light over
a large area, they need to be kept within three inches of the tops
for the plants to receive enough light. This means you will have to
mount the lights in a way that the can be raised everyday. Metal
Halide Lights Metal halide lamps put out the most light. They also
produce alot of heat. A strong fan is needed to keep room
temperatures down. MH lamps put out light mostly in the blue
spectrum. Blue light is used best by the plant during vegetative
growth. MH lights can also be used for flowering with no adverse
effects. A separate ballast is required for these lights to work.
They come in sizes from 40 to 1000W. One 1000W lamp will provide
enough light in a closet to grow four plants. High Pressure Sodium
Lights High pressure sodium lamps put out almost as much light as
MH and with less heat. Good ventilation is still required though.
HPS lamps produce light in mostly the red and orange end of the
spectrum. The plants uses this light best when flowering. HPS lamps
can also be used for vegetative growth with little slow down in
foliage production. HPS lamps require a separate ballast for
operation. Some growers switch between MH and HPS depending on what
stage the plants are in. MH is used in vegetative growth and then
the light is switched over to HPS once flowering begins. Most
growers use fluorescents to start seedlings and root clones. The
fluorescents are weaker than the MH and HPS lamps and therefore do
not stress them too much. Choose whatever light is best suited for
your situation. If your are growing in your attic go with MH or
HPS. If your growing in the closet like us, then use fluorescents.
(For the rest of ths document I will assume the reader is using
fluorescent lighting)