Water Treatment Selector: Find the Right Filter for Your Water
Choose a sensible treatment direction for city or private-well water. Start with what you know, identify what needs testing, and narrow the equipment category—without mistaking a quiz for a laboratory result.
A better order of decisions
Choose treatment by the measured problem—not by the number of filter stages
For drinking-water contaminants, start with a lab result or utility report and an exact-model reduction claim. For whole-home sediment or hardness, a main-line system may be appropriate. For lead or PFAS in drinking water, compare independently certified point-of-use products for the specific contaminant. For a positive well-water bacteria result, use safe alternative water and contact your health department before shopping. A taste or odor change does not establish safety. CDC filter selection · CDC well-water response.
Use the selector below to get a screening recommendation and a list of what must be verified before purchase. It does not certify water as safe.
Interactive water treatment selector
Answer four questions. The result changes according to your water source, evidence, concern and treatment location. All calculations run locally in your browser; the form does not submit your answers.
No answers leave this page.
Decision matrix: what to investigate first
This matrix is the non-interactive fallback and a check against overconfident quiz results. Each row identifies a treatment category to investigate, not a guarantee that a particular unit will work.
| Confirmed concern | Reasonable starting point | Important exclusion / proof |
|---|---|---|
| Positive well-water bacteria result | Safe alternative water, health department, well inspection, disinfection and retesting; evaluate appropriately certified UV only in a professionally designed plan | Do not use an ordinary carbon filter as microbial protection. UV does not remove chemicals. |
| Lead at drinking tap | Point-of-use filter independently certified for lead reduction; address plumbing source | Verify the exact model’s NSF/ANSI 53 lead claim and replacement conditions; standard number alone is insufficient. |
| PFAS | Contaminant-specific certified carbon, RO or ion-exchange treatment | Check which PFAS were tested and exact-model claims; do not assume all PFAS are covered. |
| Nitrate, arsenic or other dissolved chemical | Lab-guided treatment; compare RO or another contaminant-specific technology | Verify the specific chemical, water chemistry and certified reduction claim; carbon alone is not a universal solution. |
| Chlorine / chloramine taste | Certified carbon treatment at the drinking tap or whole-home if broader coverage is justified | Chlorine and chloramine reduction are distinct claims; removing whole-home disinfectant can have plumbing implications. |
| Sediment | Properly sized mechanical sediment prefiltration; investigate particle source | Micron size and flow must fit the actual particles; sediment removal does not prove microbial or chemical safety. |
| Hardness / scale | Measured hardness, then softener or suitable scale-control technology | A conventional sediment or carbon filter does not soften water; verify NSF/ANSI 44 claims for softeners. |
| Iron / manganese staining | Lab testing and chemistry-specific whole-home treatment design | pH, concentration, form of metal, oxidants and flow affect system selection; no one-size-fits-all cartridge. |
Basis: CDC treatment overview; NSF standards; EPA PFAS filtration; EPA WaterSense guide.
Three checks that turn a category into a real buying decision
Test the right water
City: review the utility report and consider tap-specific testing for plumbing-related lead. Well: use a qualified laboratory and local health guidance.
Verify the exact claim
Check an accredited certifier’s directory for the model and contaminant, not merely an NSF logo or a certified component.
Check operating limits
Confirm flow, capacity, pressure, feed-water quality, installation and replacement schedule. Some treatment requires pretreatment.
Shop by verified treatment goal—not by a quiz score
These are shopping searches for equipment categories, not endorsed products. Check the exact model’s third-party certification, water-quality compatibility, maintenance and installation before buying.
Certified under-sink filtration
Compare exact-model lead and other contaminant reduction claims.
Compare current optionsReverse osmosis systems
Investigate specific dissolved-chemical claims, waste water and maintenance.
Compare current optionsSediment filter housings
Compare flow, cartridge size and pressure loss for measured sediment issues.
Compare current optionsNo product has been independently selected or certified by this selector. Searches can include unsuitable products.
When the right answer is “do not buy yet”
If you have no test data, no contaminant-specific evidence or only a smell/color complaint, start with testing and diagnosis. If your public supply meets your needs and there is no identified contaminant, you may not need treatment at all. CDC: when a filter may be unnecessary.
Water treatment selector FAQs
Can this selector tell me whether my water is safe?
No. It does not test water or certify safety. Use an appropriate lab, utility information and public-health guidance.
What if I have city water but worry about lead?
Lead can come from service lines or plumbing. A utility-wide report may not characterize your tap. Consider appropriate tap testing and a certified lead-reduction device while addressing the source.
Do I need whole-house filtration for PFAS?
Not automatically. Evaluate where treatment is needed and the exact contaminant-specific performance claim. Drinking and cooking water may be handled at the tap, depending on the situation.
Will reverse osmosis solve every water problem?
No. It requires specific operating conditions and maintenance; it does not repair well contamination sources or replace professional microbial safety planning.
Does a chlorine filter remove chloramine too?
Not necessarily. Confirm a separate chloramine-reduction claim for the exact model.
Can a carbon pitcher remove bacteria from a well?
Do not assume so. Typical taste-and-odor filters are not a safe response to a positive well bacteria result.
What if I have both sediment and lead?
Different stages may be appropriate: investigate sediment pretreatment and a separately verified lead-reduction claim for drinking water.
Should I buy a water softener for hard water?
Measure hardness first and compare suitable softening or scale-control systems. Carbon filters are not interchangeable with softeners.
How do I verify NSF certification?
Look up the exact product model and specific reduction claim in the certifier’s directory and check the performance data sheet.
Does the tool store my answers?
No. The selector calculates the result within this page and does not transmit or save answers. Other site-wide analytics, if installed, are outside the tool.
Sources and methodology
Method: desk research, October 21, 2026. This tool combines public-health advice and treatment-selection principles into a transparent screening tree. It has not tested water or evaluated individual products. Its conservative safety overrides prioritize a positive microbial result and insufficient evidence over shopping suggestions.
- CDC — About Choosing Home Water Filters (water source, POU/POE, maintenance and safety).
- CDC — About Home Water Treatment Systems (different treatment types).
- CDC — Guidelines for Treating Well Water (microbial hazard response).
- CDC — Guidelines for Testing Well Water (well sampling and tests).
- NSF — Standards for Water Treatment Systems (standard types and specific claims).
- EPA — Reducing PFAS in Your Drinking Water (technology categories and certification caveats).
- EPA — Consumer Tool for Lead Filters (certified point-of-use lead reduction).
- EPA WaterSense — Guide to Selecting Water Treatment Systems (siting, softeners, efficiency and purchase decisions).