Watts: Amount of energy used (affects brightness)
CRI: Color Rendering Index. Measures accuracy of how colors look under the light by comparing them to natural daylight. For instance, if the CRI is 95, the bulb renders colors with 95 percent accuracy to natural daylight.
Lumen: A measure of brightness to the human eye.
Kelvin: A measure of heat, which affects the color of the light. Lower numbers give warmer, softer color; higher numbers emit cooler colors that are closer to daylight. Noon daylight is about 5500 degrees Kelvin.
"What are those numbers on the end of my bulb?" Most tube bulbs have two numbers on one end: the length, and another number preceded by a "T." Divide this number by 8 to get the diameter of your bulb. For example, a T8 bulb is one inch in diameter; a T12 is 1 1/2".
Ballast: The mechanism that controls the voltage flow of the fluorescent light. Electronic ballasts use less electricity than regular (analog) ballasts and also emit fewer electromagnetic fields. In addition, electronic ballasts have little or no flicker. If you have analog ballasts and want to replace them with electronic ones, you can buy them at an electrical supply store. If you are buying tube lights and don't know what kind of ballast you have, then buy the
Fluorescent Daylite (either 20- or 40-watt) Tube, which can be used with either analog or electronic ballasts.
We also recommend parabolic "egg crate" diffusers (open-grid coverings) for all fixtures that use
full-spectrum tubes; standard plastic covers block most of the UV benefits of full-spectrum light. These diffusers can be purchased at electrical supply stores. You can also drill holes in your regular diffuser.
Go back to full-spectrum fluorescent lighting products.
