Replacing your Aqua Flo UVSS-10 & UVSS-10M Lamp every year is important to ensure consistent water quality. Though UV lamps rarely burn out, they will lose their ultraviolet effectiveness (disinfection power) over a 12 month period. 
Application: 
The Aqua Flo 89501 UV Lamp is the heart of the UVSS & UVSS-M systems, which can disinfects from 7.7 to 20 gallons per minute, when prefiltration is effectively maintained. It is also important to replace your quartz sleeve if damaged or if it cannot be cleaned by non-abrasive methods.
If it is time to replace your Quartz Sleeve:

• Use UV89511 Quartz Sleeve with UVSS-10 & UVSS-10M Systems
  
• Recommended to replace your 89501 UV Lamp every year