Grow Lights - Two Basic Types
Fluorescent Grow Lights - Since fluorescent grow
lights produce just a fraction of the power of Metal Halide and High
Pressure Sodium grow lights, they are generally unsatisfactory for
general use. They are useful for starting new plants and for some
compact hydroponics projects, but must be placed very close to the
plants. To cover a 2′ by 4′ area, you’ll need a minimum of four
54-watt 4′ fluorescent bulbs, placed as close to the growing plants
as possible. Even then, results may not be satisfactory and
producing fruits and vegetables will be difficult. Still,
fluorescent grow lights are well suited for the very early stages of
plant growth, and are often used to start new plants.
High Intensity Discharge - Both Metal Halide (MH)
and High Pressure Sodium (HPS) bulbs fall into this category. Their
intensely bright light makes them ideal for lighting indoor
plantings. Both require Reflector housings and Ballasts to operate.
In almost all cases, the same reflectors and switchable ballasts can
be used to for both MN and HPS bulbs. The area that these forms of
lighting can cover depends on their wattage. Ranging from 150 watts
to 1000 watts, a single fixture can cover from a small
self-contained hydroponics garden up to 20-40 sq. ft. Large
installations will require multiple fixtures. Since HID lamps create
a great deal of heat, proper venting or even ducting and fans are
usually needed.
Metal Halide – These bulbs produce an intense light
of blue-white spectrum, excellent for vegetative plant growth.
A plant grown under a metal halide light will often exhibit
increased leaf growth and strong stem and branch development.
They are less suited for the flowering and fruiting stages of
most plants.
High Pressure Sodium – These lamps produce an orange
light, which simulates the autumn sun. This light is best for
fruiting and flowering – flowers and fruit will be larger and
more prolific when these lights are used. Flowers and vegetables
finished off under high-pressure sodium will show tighter,
stouter blossoms with increased yields. High-pressure sodium
lights are often used in commercial greenhouses. If there is to
be only one light source for the entire life of a flowering
plant, HPS is the best economical choice. Many indoor and
hydroponics gardeners switch between MH and HPS bulbs, depending
on the growth cycle. Almost all lighting systems we carry support both types of HID bulbs.
LED Grow Lights - Grow lights using efficient LED
sources are relatively new. Early versions of these lights had
insufficient power to be effective for most growers. Recently a new
high-density LED array technology was introduced, which packs more
LEDs and offers more power than previous LED Grow Lights. Important Grow Lighting Rules
Choose The Right Light – when choosing a light
source the requirements of the plant you are growing is
important. Most vegetables, herbs and flowering plants require
high levels of light, while some tropical plants including
orchids and African violets will thrive at lower light levels.
Have Enough Light – the biggest mistake people make
when purchasing grow lights is not getting enough light. It is
always possible to reduce the level of light by moving the light
farther away, but it’s not possible to add light by moving the
lamp closer, since the coverage area decreases.
Maintain the Proper Distance – Fluorescent lights
need to be 1 to 4 inches from the plants. High intensity
discharge lights should be 1 to 3 feet from the plant. And make
sure you change your bulbs on a regular basis. Fluorescent and
HID bulbs will last about 15,000 hours, but they lose 25%-35% of
their intensity after 4-6,000 hours. You eyes won’t be able to
see this loss of light because they adjust, but your plants can
feel it.
