There are many kinds of Grow lights for your chosen in market, that might be a headache to a new grower when make a choice. I list all of them below that hope to make clear:

The least expensive lights to purchase cost around $30. These incandescent lights work well for specific plants where the light is placed a minimum of 24" from the plant. These lights get extremely hot so they must be used with care. Spot grow bulbs, color corrected incandescent lights, install easily and are good for use with a specific plant or a small grouping of plants. Most spot incandescent bulbs last less than 1,000 hours. Some light fixtures come with a clip handle so you can put them exactly where they're needed.

Florescent grow lights are a common choice for homeowners. Florescent lights are reasonably energy efficient and relatively easy to install. A typical florescent bulb will last approximately 20,000 hours. Florescent light is typically on the blue end of the spectrum. Blue light encourages bushy compact growth which makes them perfect for seed starting. The blue light is also cool to the touch making it possible to place lights within just a few inches of the seedlings.

New full-spectrum florescent lights provide the red spectrum as well to encourage blooming. Combining the lights in a fixture makes for even, all around growth. The next generation in florescent lighting includes the new T-5 lights. These new lights have extremely high output but are energy efficient and long lasting. The T-5 lights triple the light output of normal florescent lights without increasing the wattage. Plants absorb a high percentage of T-5 lighting because the fixtures function well very close to plants. High output bulbs require a high output fixture to operate, so the bulbs and normal florescent fixtures will not work together.

Some commercial growers use High Intensity Discharge lights because they have extremely high output and cover a wide area. HID lights hang high above plants (hanging height determined by the wattage) so the light works well for large growing areas. Operating HID lights require a ballast to deliver power to the lamp and fixture for the light. Most fixtures have a reflective hood which directs light back towards plants. HID lights emit high heat, so they must be placed away from plants to avoid burning the leaves. There are two types of HID lights, Metal Halide and High Pressure Sodium.

Metal Halide produces blue light that most closely resembles natural light. This would be the preferable light if used as the primary lighting because plant growth most closely resembles plants grown outdoors. This type of lighting is excellent for areas that do not get natural sun.

The second type of HID lighting, High Pressure Sodium, is excellent for supplemental lighting in a greenhouse because the red light enhances flowering. The bulbs also last substantially longer than Metal Halides. Used as supplemental lighting, the orange-red light does not create leggy growth. It is interesting to note that plants do not appear as healthy under the reddish light as the blue because our eyes do not adjust well to the color. High Pressure Sodium bulbs have a long life; however, they should be replaced according to manufacturer's instructions. Bulbs continue to light beyond their useful life, however, the energy draw increases dramatically and the output lowers significantly.

Metal Halide and High Pressure Sodium lights generally do not use the same fixtures, however, some fixtures are convertible. With convertible fixtures, bulbs swap easily. A simple flip of a switch converts the fixture after changing the bulb. This is a good option for serious growers who want the benefits of compact growth, blooms and energy efficiency. The start up cost is not insignificant. However, the combination offers a tremendous amount of control in the greenhouse.

The newest type of grow lights use LED technology. One major advantage to the LED grow lights is the small size. LED grow lights are only a few inches in diameter and are easy to mount. In some greenhouses, LED grow light may be the only practical light option. Hanging most grow lights requires a strong greenhouse structure and a place to hang the lights. LED grow light weigh a fraction of other lights and are easy to configure where needed. According to LED manufacturers, LED grow light maximize blue and red light to provide and excellent balance for plants. They do not have much green-yellow light. Since humans see green-yellow light best LED grow lights appear dim to our eyes. And the most important advantage is that LED grow light is green technology which don't contain any harmful substance like HID or other traditional grow lights, and it can save 70-80% electricity bill than using HID lamp. This is newest technology used for plant growing now and becoming more and more popular.