There are several different types of technology when selecting a grow light bulb for your indoor plants. All of these indoor grow lights are used in grow light fixtures, most of which have a reflector to aim the light down at your growing bed. Mounting height and distance from the plants will vary based on the growth cycle, type of grow light bulb, and type of plant. These plant lights may be used in greenhouse setups, small-scale operations and plant grow facilities. 

• Ceramic Metal Halide Grow Lights or CMH grow lights come in both warm and cool colour temperatures. With less radio frequency (RF) interference than LEDs, these lights are more efficient than other HIDs of the same wattage. Just like standard metal halide grow lights, the cool white light helps stimulate leaf growth. 

• High Pressure Sodium Grow Lights or HID grow lights produce high output ideal for stimulating plant growth. HPS grow lights emit strong, warm white light that promote flowering.

• Metal Halide Grow Lights or MH grow lights emit strong, cool white light that results in compact, leafy vegetation. This makes them most popular for leafy vegetables like lettuce and herbs. Life hours range from 3,000 to 10,000 hours.