Collection: Under Sink Water Filters

Under Sink Water Filters

An under sink water filter treats drinking water at the point where it is used, mounted inside the cabinet and plumbed into the cold line feeding the kitchen faucet or a dedicated filtered water tap. The system does its work out of sight, which is a large part of why homeowners choose this format over a countertop unit or a pitcher: the counter stays clear and filtered water is always on tap.

Under sink systems come in several configurations. Single stage units run water through one cartridge, usually carbon based. Multi stage systems put a sediment cartridge ahead of one or more carbon stages so each stage handles what it is suited to. Reverse osmosis systems add a membrane and a storage tank for a further stage of treatment. Cartridges in these systems are designed to reduce sediment and rust along with the chlorine taste and odor common in municipal water, and each product description states what that specific cartridge is built to reduce.

• Single stage carbon systems for taste and odor
• Multi stage systems that pair a sediment cartridge with carbon
• Reverse osmosis systems with a membrane and a storage tank

EverPure, Whirlpool, Doulton, and Pentek are among the manufacturers represented in this category. Matching a replacement cartridge is a matter of reading the model number off the housing or the old cartridge, since housings differ in thread, length, and diameter between manufacturers, and a cartridge that is close is not close enough to seal. Faucet adapters, tubing, and mounting hardware are listed alongside the systems that use them, which matters on a replacement where the existing plumbing stays in place.

Cartridges in an under sink system are consumables. Most system manuals suggest an interval measured in months or in gallons, and a change in taste or a drop in flow at the faucet are the everyday signals that a cartridge has reached the end of its useful life. A subscribe and save plan keeps a fresh cartridge arriving on that schedule, so the system that is easiest to forget about stays current.