The best filtration system for your home starts with your water, not the brochure

Advertised prices, verified

How to choose a filtration system that fits

1. Test the water first. Get a real result before buying anything: a city report tells you what the utility sends, but a tap-level test or a lab panel tells you what arrives after your own pipes. Our water testing guide walks through both routes and what each one can and cannot see.
2. Match the media to the contaminant. Activated carbon handles chlorine, taste and odor. Reverse osmosis strips dissolved solids, lead and PFAS at a single tap. Sediment cartridges catch grit before it reaches finer stages. Iron and sulfur need oxidizing media. No single cartridge does all of it well.
3. Decide point of use or whole house. If the complaint is drinking water taste or a dissolved contaminant, an under-sink unit at the kitchen tap is usually the efficient answer. If the problem reaches every fixture, like sediment, chlorine smell in the shower or staining, size a whole-house system on the main line instead.
4. Compare verified prices and plan for cartridges. Use the table on this page to compare systems at their sellers' published prices, then check the replacement cartridge cost and change interval before committing. A cheap housing with expensive cartridges often costs more over a few years than a dearer system with affordable refills.

The main system types, and the problem each one actually solves

Whole-house carbon systems sit on the main line and treat every tap. They are the right call when the complaint is chlorine or chloramine taste and smell throughout the home, and they protect softener resin and appliances downstream. They do not remove dissolved solids, so they are not the tool for lead, nitrates or PFAS on their own.

Reverse osmosis systems push water through a membrane fine enough to reject dissolved contaminants, which makes them the default choice for drinking-water concerns like lead, arsenic, nitrates and PFAS. Most homes run RO at one tap rather than the whole house, because the membrane works slowly and produces reject water in the process.

Specialty media rounds out the picture: sediment cartridges for grit and cloudiness, air-injection or greensand systems for iron and sulfur on wells, and UV purifiers where bacteria are the concern. Well owners very often need a treatment train of two or three of these in sequence rather than one box.

Where buyers overspend, and where they underspend

The most common overspend is buying whole-house treatment for a drinking-water problem. If the issue only matters at the glass, a point-of-use system at the kitchen tap treats the water you actually drink and leaves the lawn, toilets and laundry out of the bill entirely.

The most common underspend is skipping pretreatment. Sediment or iron sent into a carbon bed or an RO membrane shortens its life dramatically, so the money saved up front comes back as early cartridge and membrane replacements. Sequence the stages so each one protects the next.

Common questions

Is a whole-house filter better than an under-sink filter?

Neither is better in general. Whole-house units fix problems that reach every fixture, like chlorine smell or sediment, while under-sink units treat drinking water more thoroughly at one tap. Many homes run one of each for different jobs.

Do I need a water test before buying a filtration system?

Yes. Filters are contaminant-specific, and a system aimed at the wrong problem does nothing. A city report or a tap-level lab test tells you which media you actually need before you spend, and it gives you a baseline to prove the system works.

How much does a good filtration system cost?

It depends on scope: single-tap systems sit at the low end and whole-house treatment trains at the top. The verified price table on this page shows current vendor pricing, and the running median is $1,531, so compare against that rather than a salesperson's anchor.

Will one filtration system remove everything?

No single system covers every contaminant. Carbon, reverse osmosis, sediment, iron media and UV each solve different problems, which is why well owners in particular usually stack two or three stages in sequence rather than relying on one unit.

Browse by system type

• Compare Water softeners on advertised prices
• Compare Salt-free softeners on advertised prices
• Compare Whole-house filters on advertised prices
• Compare Reverse osmosis systems on advertised prices
• Compare Shower filters on advertised prices
• Compare Countertop filters on advertised prices
• Compare Refrigerator filters on advertised prices
• Compare Iron filters on advertised prices