Plumbing Picks is reader-supported. As an Amazon Associate, we earn from qualifying purchases at no extra cost to you.
Quick answer from a licensed plumber: Get an under-sink filter for better-tasting, cleaner drinking water at the kitchen tap — cheaper and easy to DIY. Get a whole-house filter if sediment, chlorine, or hard water affects every tap, shower, and appliance. Many homes benefit from both.
Under-Sink vs Whole-House at a Glance
| Under-Sink | Whole-House | |
|---|---|---|
| Covers | One tap (kitchen) | Every tap, shower, appliance |
| Install | Easy DIY | Harder — at main line |
| Cost | $ | $$–$$$ |
| Best for | Drinking-water taste | Sediment, chlorine, hard water |
When an Under-Sink Filter Is Enough
If your water is generally fine but you want better drinking water, an under-sink water filter installs in under an hour and treats just the tap you drink from.
When You Need Whole-House
Sediment clogging fixtures, chlorine smell everywhere, or hard-water scale calls for treatment at the main line. A shower head filter is a cheap middle-ground for chlorine in the shower.
First, Test Your Pressure
Before buying, check pressure with a water pressure gauge — filters slightly reduce flow.
The Plumber’s Verdict
Most people: start with an under-sink filter; add whole-house only if a water test or symptoms justify it. Put a water leak detector near any filter.
FAQ
Do I need a whole-house water filter?
Only if sediment, chlorine, or hard water affects every tap. For drinking-water taste alone, an under-sink filter is sufficient.
Will a water filter lower my water pressure?
Slightly. If pressure is already low, test first and pick a higher-flow filter.
Can I install an under-sink filter myself?
Yes — most are a straightforward DIY job under an hour.
For the cleanest drinking water at one tap, a reverse osmosis system filters far more than a basic carbon filter, with a couple of trade-offs worth knowing.
Where to Buy
Check current prices on Amazon: Under-sink water filters · Whole-house water filters.
Fix the 12 Most Common Plumbing Problems Yourself — Free Plumber’s Handbook — including how to tell if your water heater is about to fail
Step-by-step fixes for the 12 most common problems — and exactly when to call a pro. Free and instant, from a licensed plumber. Save hundreds on calls you didn’t need.