This bulb needs to be changed every 12 months.  You may get a "blb", 616 error on your control panel.  It is a reminder to change the bulb.

• High-Intensity, ultraviolet light-emitting 5 watt lamp. 7" length.
• Lamp life exceeds 13,000 energized hours
• Permanent PVC protective caps and shock dampening spring ensure lamp will not become loose during transit
• Internal 316L stainless steel sealing mechanism ensures that quartz shroud protecting the lamp will not distort or leak
• Long life electronic lamp ballast
• Treats 99.9% of waterborne pathogens
• UV Lamp continues to emit dosage of 30mg/cm2 near end of life

How to replace CLEARRAY® Bulb
CLEARRAY® BULB REPLACEMENT AND QUARTZ TUBE MAINTENANCE
1. Turn the breaker to the spa OFF. We recommend that you drain your spa. Disconnect the CLEARRAY® System from the controller, Figure 
2. Once the UV lamp has cooled off remove the CLEARRAY® System enclosure cover and gasket by removing the four screws.

DANGER: NEVER REMOVE COVER WITHOUT FIRST TURNING OFF AT POWER SOURCE.