Jacuzzi ProTech LCD Owner's Manual page 38

To ensure optimum performance, clean and reuse the skimmer bag and both
cartridges once a month, or as needed. ALWAYS TURN POWER TO SPA
OFF BEFORE CLEANING THE FILTER CARTRIDGES! Refer to the filter
cleaning/replacement procedure below:
Page 34
Submerge both filter cartridges in
spa. Tilt threaded end upward to
remove trapped air bubbles from
each cartridge, then keep both
cartridges submerged for step H.
Trapped
Air
Bubbles