What is the difference between a BT-56 and BT-37 metal halide lamp

BT-56 and BT-37 correlate to the size of the glass envelope surrounding the actual arc tube of the lamp. BT-56 lamps are larger than BT-37 lamps and are commonly operated in a vertical orientation in parabolic style reflectors. BT-56 style lamps will not fit inside many horizontal reflector designs.

How often should I replace my grow bulbs?

Whether fluorescent, sodium, or halide, we recommend to replace light system bulbs every 1 to 1.5 years if ran for a minimum of 12 hours per day. Although they may still ignite for multiple years, quality of light to the plants has degraded after this time of continuous use. The appropriate time to replace bulbs is at it’s “Economic Life” rather then the rated life. This is typically calculated at 60% of the bulb’s rated life.

Should my HID lights hang vertical or horizontal for maximum penetration?

Studies have shown that a horizontal positioned bulb and reflector unit will provide superior light penetration compared to vertical orientation. However, both styles are acceptable for cultivation. Some bulbs are designed to be hung in horizontal position. This designation will be listed on the bulb as a “horizontal” position bulb. These bulbs should be hung in the horizontal position.

How do I know if I have screwed in a light bulb all the way to prevent arcing? (For universal positioned lamps)

(1) First check to see if the tab in the back of the socket is tilted upward at 15 degree angle or greater.
(2) Make sure your socket will accept compatible threads from the lamp (bulb). Typical HID bases are E39.
(3) Firmly screw the lamp clockwise until you feel a firm hold. You should feel an initial restriction when the tip of the lamp hits the socket tab. In some situations, this may not be enough as you may be able to get up to ½ turn more once you feel initial resistance. Be careful not to over tighten as this may crack the glass insulator and cause the outer glass jack to crack at the threaded base.
(4) Once inserted, if the lamp seems loose, unscrew it and try again. If the connection does not seem correct, contact a local electrical contractor or call PARsource for further troubleshooting.

L70 lifespan. What does it mean?

L70 is an industry standard to express the useful lifespan of an LED. It indicates the number of hours before light output drops to 70% of initial output.