Both fluorescent fixtures and HID lamps use a much higher voltage of electricity than standard 110 volt house current. Fluorescent fixtures contain a ballast or transformer that converts electricity to its proper voltage. HID lamps sometimes come in a fixture containing the ballast, but most of the units made for indoor gardens are designed with the ballast remote (separate, but connected by an electrical cord) from the lamp and reflector.
HIDís with remote ballasts are much more convenient than units with the ballasts enclosed since they weigh less. 400 watt ballasts weigh about 28 lbs. and 1000 watt ballasts weigh about 40 lbs. It is much harder to manipulate and secure a heavy object like that overhead than it is to just leave it near ground level attached to the lamp by an electrical cord. The lamp is hung from the ceiling using cord or wire attached to a hook or pulley.
Outdoors, plants receive light from many directions. Over the course of the day the sun bathes plants in light starting in the east and travelling west. Leaves shaded during part of the day are under full sun at other times.
Indoors, using a stationary light, some plant parts are always shaded while others are always lit. With a light in the center of the garden, plants closer to the source receive brighter light than those at the periphery.
Reflectors with different shapes distribute light in varying patterns. A good quality reflector will spread the light evenly over the garden. Still, a light coming from a single stationary source leaves some areas in permanent shadow.
Light movers were invented to solve these problems. The movers carry the lamp over a fixed course so that entire the garden comes directly under the light part of the time. These units are manufactured by a number of suppliers and use several innovative techniques to move the lamps. Some of them move the lamps quickly, so that the light passes over the garden in less than a minute. Other movers take 40 minutes to traverse the course. Both types improve light distribution in the garden. As a result, the plants grow at an even rate. Since the plants are not stretching in one direction to the light, they grow straighter, with more symmetry.
The rotating units seem most effective in a square room, while the shuttles, which go back and forth, seem best in rectangular or odd shaped spaces.
Closet cultivators have found that electrically generated light is precious so any generated is best conserved. Efficient indoor gardens must reflect back the light straying out of the perimeter. Growers cover walls which cannot be painted with flat white paint, with aluminum foil, Astrolon or mylar. This is extremely important. Any light which hits a dark surface is absorbed and converted into heat, rather than being used in the garden. Reflective material is easily hung using staples tacks or tape. There are several ways growers make walls very reflective:
White reflective paint. Flat white paint diffracts the light so that it is distributed more evenly through the garden. Off-whites absorb a considerable amount of light so they are avoided. The best paint for indoor gardens is greenhouse white which is formulated for maximum reflectivity.
Aluminum foil is used to line the walls. It is highly reflective and very inexpensive. Its down sides are that it is noisy when it moves with a breeze and has little tensile strength, so that it tears easily when not attached to a surface. It is usually not used where it will be moved around or used for a curtain or doorway because it crinkles and tears easily. When the dull side out is used the reflection is defused rather than just reflecting hot spots. Eighteen inch wide heavy duty rolls are the easiest to work with. In places where heat must be conserved fiberglass insulation with aluminum reflective surface is often used to line the walls.
Silvered gift wrap comes in rolls or sheets. it is composed of a thin metal foil glued onto paper wrap. It is very reflective, easy to use and inexpensive. It is available from some wholesale gift paper houses or from gift shops.
Styrofoam is used in cool spaces where heat must be conserved. The walls can be lined with styrofoam insulating material which comes on a roll or in sheets. (available in some home improvement stores). It is extremely reflective. The rolls come in several widths, and is about 1/8" thick.
Mylar. Grow stores sell silvered mylar which is extremely reflective. While mylar reflects most of the light; it is not opaque and it allows a dim image through. The plastic film creases easily.
Astrolon is a silvered plastic which is extremely reflective, but not opaque. The thin plastic is quilted and very pliable It is very durable and very reflective.
Step by Step
- Successful closet cultivators know that light should be distributed evenly throughout the grow space. Light movers or several lights may be indicated.
- Smart growers line the walls of the growing area with a reflective surface to conserve light.