Start here
Most people start by buying a filter. Start by finding out what is actually in your water: the right fix, and whether you need one at all, depends on it.
Find out
Step 1: Find Out What's in Your Water
Start with your utility's report or a test, not with a filter: the right fix depends entirely on what is actually in your water.
Fix it
Step 2: Choose a Filter or Softener That Fixes It
Match the treatment to the problem, then check the certification listing before you buy: a claim on the box is not a certificate.
Keep it working
Step 3: Keep Your System Working
Cartridge changes, softener salt, sanitizing and retesting: a filter past its rated capacity can stop doing its job.
On a private well? Nobody tests it for you, so testing comes first. Read Well Waterbefore anything else.