Pre-installation filter check
The Waterdrop WD-SHF-06A ships with the filter cartridge pre-installed in the showerhead body. Before installation, verify the cartridge is fully seated -- unscrew the cartridge housing cap (the section of the showerhead body that accesses the filter), check that the cartridge is flush-seated against its housing, and re-secure the cap finger-tight. Do not over-tighten the housing cap -- it requires only enough torque to seat the O-ring seal.
Showerhead installation
Remove the existing showerhead from the shower arm. Clean the arm threads. Apply 3 wraps of Teflon tape clockwise to the arm threads. Thread the Waterdrop showerhead clockwise by hand until the inlet washer is snug against the arm face. Add one quarter-turn with an adjustable wrench (cloth-protected on the finish). Turn on the water -- do not touch the spray face for the first 30 seconds as the first flush may carry some filter media fines.
First-use flush
Run the shower at full flow for 2-3 minutes before first use. The first 30-60 seconds may show slightly discolored water (grey or faintly brown) from the activated carbon or KDF media. This is normal and clears within 2 minutes. If discoloration persists beyond 5 minutes, the cartridge was improperly seated -- shut off water, remove the showerhead, re-seat the cartridge, reinstall, and flush again. A correctly seated cartridge should produce clear water within 2 minutes.
Cartridge replacement procedure
At the end of filter life (approximately 30,000 gallons): (1) Shut off shower supply. (2) Unscrew the showerhead from the arm. (3) Locate the cartridge housing section on the showerhead body. (4) Unscrew the housing cap counterclockwise. (5) Pull out the spent cartridge. (6) Insert the new Waterdrop replacement cartridge (model number matches the showerhead model). (7) Replace the housing cap finger-tight. (8) Reinstall the showerhead on the arm. (9) Run a 2-minute first-use flush. The entire cartridge swap takes approximately 5 minutes.