Concern → evidence → treatment
Do not shop by contaminant name alone.
The same symptom can have multiple causes, and the same technology can carry different verified claims from one model to another. This library shows where responsible research begins.
Aesthetic concern
Chlorine taste and odor
Read the utility’s disinfectant entry and note whether the issue occurs at every tap, only in hot water, or only after water sits.
Exact NSF/ANSI 42 chlorine or chloramine claim
Disinfectant chemistry and contact time matter; carbon systems are not interchangeable. Open guide →
02Water characteristic
Hard water and scale
Obtain a hardness result in mg/L as calcium carbonate or grains per gallon. A utility range may not describe the exact home at every season.
NSF/ANSI 44 ion exchange or a narrow conditioning claim
Hardness is different from chlorine, sediment, iron, or a health-effect contaminant. Open guide →
03Health concern
Lead in drinking water
Follow local health or utility sampling instructions for the specific tap. Record stagnation time, aerator condition, sample sequence, and the laboratory result.
Exact certified lead-reduction claim
A utility report may not capture lead contributed by a home’s service line or plumbing. Open guide →
04Health concern
PFAS and home water filters
Check the utility’s current PFAS disclosure or use a qualified laboratory. Record the named compounds, reporting units, reporting limits, and sample date.
Exact PFOA or PFOS claim under NSF/ANSI 53 or 58
Certification thresholds and named compounds must be read carefully. Open guide →
05Well-water chemistry
Iron and manganese in well water
Use a certified laboratory result that includes total iron, manganese, pH, hardness, and other locally relevant well-water parameters.
Chemistry-specific treatment with adequate backwash
A sediment cartridge is not a universal solution for dissolved iron or manganese. Open guide →
06Microbiological concern
Bacteria and microorganisms in private wells
Follow state or local sampling instructions and use a certified laboratory. If a result or advisory indicates a health risk, follow public-health directions immediately.
Source correction and validated treatment
Do not select UV from symptoms alone; pretreatment and system class matter. Open guide →