Unscrew the pump from the Katadyn water filter, and remove the O-ring. Rinse any buildup from the O-ring, and rub silicon lubricant on it. Replace the O-ring, and screw the pump back in place.
Remove the prefilter from the Katadyn water filter pump. Rinse the prefilter with water, and wipe it with a brush to remove any builtup. Place the prefilter back into the water pump.
Remove the Katadyn water filter cartridge, and rinse it with treated water to remove any sediment buildup. Place the cartridge back into the water filter.