How often should I replace the UV bulb in my UltraKlean Pond Filter? April 18, 2026 02:38 Replace every 12 months at 24-hour operationBulb may last:2 years at 12-hour setting4 years at 6-hour settingEven if lit, UV output declines over time. Related articles UltraKlean Pond Filter Winter Maintenance Videos and Troubleshooting Can I replace the UV bulb myself? How often should I backwash my UltraKlean Pond Filter? How often should I clean my UltraKlean Pond Filter?