The clear quartz tube that keeps the UV lamp dry while letting UV-C light through into the water. Ordinary glass blocks UV-C, which is why this is quartz and why a cracked or heavily scaled sleeve stops a clarifier working even though the lamp still lights.
Which sleeve fits what
- 5w — InPond 5 in 1 2000 and 3000
- 9w — InPond 5 in 1 6000 and InPond 6 in 1 9000
- 18w — Midipond 10,000 / 20,000 filter, Pro-UVC 18w
- 24w — Midipond 14,000 / 28,000 filter, Pro-UVC 24w
- 36w — Pro-UVC 36w, and Pro-UVC 72w (which runs twin 36W lamps, so a 72w unit needs two sleeves)
Minipond, Clean Pond Machine and the 13w pressure filter use different sleeves and are not cross-compatible.
Maintenance
Wipe the sleeve at every service. Limescale and algae film on the outside of the quartz block UV just as effectively as a dead lamp. Replace the sleeve if it is scratched, etched or cracked; replace the lamp itself annually, because UV output falls away long before the lamp stops glowing.
Handle with care
Quartz is brittle and the sleeve is thin. Support it at both ends when removing it, and never lever it out against the housing.