A water filter removes contaminants (like bacteria, lead, or chlorine). A water softener removes dissolved minerals (calcium and magnesium) that cause hard water scaling, but it generally does not purify water for drinking.

Water filters remove a wide range of impurities, including physical sediment (dirt, rust), chemicals (chlorine, PFAS, VOCs), heavy metals (lead, mercury), and microorganisms (bacteria, parasites). The specific contaminants removed depend entirely on the filter technology used.

• Activated Carbon Filters: Found in most pitchers and faucet attachments, these use adsorption to effectively remove chlorine, VOCs (pesticides, herbicides), PFAS (“forever chemicals”), and unpleasant tastes and odors.
• Reverse Osmosis (RO) Systems: These force water through a semipermeable membrane to remove nearly all dissolved minerals, salts, heavy metals (like arsenic and lead), fluoride, and nitrate.
• Ion Exchange Filters: Often paired with carbon, these beads swap harmful heavy metal ions (like lead and copper) with harmless ones (like sodium or potassium).
• UV Purifiers: Instead of physically capturing particles, these use ultraviolet light to sterilize and kill bacteria, viruses, and protozoa.
• Sediment Filters: These act as physical sieves to block large physical debris like sand, silt, and rust from passing into your plumbing.

Filter lifespans vary based on the model and how much water your household uses. Generally, RO membranes last 1 to 2 years, while carbon block and sediment filters should be replaced every 3 to 6 months. Failing to replace filters can clog the system or cause contaminants to leak back into your water.

It depends on your needs. A point-of-use system (like an under-sink RO or a faucet-mounted filter) is designed just for your drinking and cooking water. A whole-home (Point-of-Entry) system treats all the water as it enters the house, protecting your plumbing, fixtures, and appliances from sediment and hard water.