Quick take
Inspect and clean the sleeve during scheduled lamp maintenance. Replace it if cracked, chipped, permanently clouded or unable to be cleaned back to a clear surface.
Why sleeves foul
Hardness scale, iron and manganese deposits can accumulate on quartz, especially when upstream treatment is inadequate.
Cleaning frequency
Annual inspection is a practical baseline because it aligns with lamp maintenance, but difficult water can require more frequent cleaning.
When replacement is justified
Physical damage, permanent etching or stubborn deposits that cannot be removed safely can justify a new sleeve.
Prevent the problem upstream
Better sediment, iron and hardness control can reduce sleeve fouling and preserve delivered UV intensity.