Indoor growing has gained popularity as people have discovered new lighting technologies, and those technologies have become less expensive. It is possible to set up an entire grow room or grow basement for winter vegetable production, or to simply light a small bookshelf for an indoor tropical flower garden.
Depending on the size of your growing space, the amount of light the plants need, and the initial expense you are willing to pay, an effective grow light setup is available for virtually any type of situation.
High Intensity Discharge
High-intensity discharge lights include metal halide and high pressure sodium. These give you the best bang for your buck for indoor grow lights. They come in wattages from 50 to 1500 watts, but 1000 watts is the most common. The quality and intensity of the light put out by these lamps make them far superior to other lights. They are perfect for plants that need strong lighting, similar to full sunlight, in order to reach optimal production levels. They are also beneficial for larger grow areas where it may not be feasible to have fluorescent tubes within inches above every single plant.
The disadvantages of these setups is that they put out a lot of heat, which needs to be vented and can be expensive to set up initially.
Standard fluorescent T12 tubes are a staple for indoor growing. The low cost, availability and ease of installation often make these the best choice for small grow areas with low to medium light requirements. They do not put out as much heat per watt of power burned than other types of light so it is possible to move the top of the plants to within an inch of the tubes. Be careful to not let the plants touch or they will burn.
Compact fluorescent (also known as power compact or T5) lights are a recent technological advance in lighting. These tubes put out a considerably larger amount of light per watt of power burned than traditional T12 fluorescent tubes. They also emit more heat. The heat-for-intensity trade-off is worth it for higher light-loving plants that are being grown in a small space. They are not nearly as hot as high intensity discharge lamps,
The new energy-efficient screw-in incandescent replacement bulbs are compact fluorescents. These make good plant lights for spot lighting and supplemental lighting. The coil arrangement of the tube makes them less efficient for dispersing light in one direction, unlike linear-shaped compact fluorescent tubes; but they will grow plants well when something more than a regular T12 light intensity is needed.