High Intensity Discharge (HID) Lamp Specifications

Color rendering Index (CRI)

Color rendering is a measure of lighting quality. It is measured on an index from 0-100, with natural daylight and incandescent lighting both equal to 100. Lamps with a high color rendering index make objects appear more true to life. Plants can grow better with a higher color rendering index light source. But generally the higher the CRI the lower the lamp efficiency.

Color Temperature

Color temperature is a measure of the color appearance of light not the actual temperature. Light sources that appear bright white to blue-white have a high color temperature (3600K and above) and are described as "cool". Sources that appear yellow-white to red-white have a low color temperature (3400K and below) and are described as "warm". Daylight is considered to be around 5500K and plants grown under this light do quite well. The cost of the lamp increases as the color temperature goes up because of the rare materials required to fill the arc tube.


A lumen is the unit that expresses the total quantity of light given of by a source, regardless of direction. A lumen is defined as the amount of light falling on a surface of one square foot, every point of which is one foot away from a source, (a section of the inside surface of a sphere) of one candlepower. A uniform source of one candlepower placed in a sphere emits 12.57 lumens.

Initial Lumens

Initial Lumens is the measurement of the intensity of the lamp Initially. Lamps do get dim over time and replacing them after 60% of the rated life is recommended for best performance.

Description Initial Lumens CRI Color Temp Life
1000 watt Sodium 130000 21 2100 24000
600 watt Sodium 89000 21 2100 18000
400 watt Sodium 50000 21 2100 24000
250 watt Sodium 28500 21 2100 24000
1000 watt Halide110000 65 3700 10000
400 watt Halide 36000 65 4000 20000
250 watt Halide 20500 65 4000 10000

The table above is not a product guarantee, the specifications will vary slightly between different lamp manufacturers. The numbers above are an average of all our lamp suppliers specifications.

Home | Products | Learning Center | About Us | Returns & Refunds | Shipping | Privacy | Testimonials | Contact | Login | View Cart |

Copyright 1992-2016 Greentrees Hydroponics