the electricity is not turned into light but into
heat. There are newer types which are a
little more efficient, but the increase in light
is of only marginal help.
VHO (very high output)
FLUORESCENTS are also available. They
use about 3 times the electricity of standard
fluorescents and emit about 2½ times the
light. While they are not as efficient as
regular fluorescents, each tube delivers 2½
times more light to the garden.
The inner surface of each fluorescent
tube is covered with a phosphor which
glows when tickled by the flow of electrons
through it. Fluorescent tubes are named for
the spectrum of light which they emit. Some
of the spectrums are more conducive to
plant growth than others. Deluxe warm
white, warm white, and deluxe cool white
are three types which promote fast growth.
Special grow bulbs concentrate light in
areas used most efficiently by the plant.
However, they are fairly dim and plant
growth is slowed when they are used.
HIGH INTENSITY DISCHARGE LAMPS
High intensity discharge lamps (HIDs)
are easier to use and more efficient. Low
wattage HIDs are sometimes sold for
household outdoor use. Large wattage
lamps are used to light yards, streets,
parking lots, stadiums and other large
areas. They come in two versions:
METAL HALIDES or MH lamps emit a
white light that looks slightly bluish. They
are used to light stadiums, convention
centers and other large areas where a