Treatment intelligence · comparison

Compare Water Treatment Technologies

Compare what each published treatment mechanism may address, where it fits, what upkeep it requires, and which limitations must remain visible.

Start with my water Understand certification

6 published technologies7 contaminant families7 standards named

At a glance · descriptive, not ranked

Which families each method may address

Select a row to add it to the side-by-side comparison below.Tap + Compare to add a method to the side-by-side view below.

PFAS	Metals	DBPs	VOCs	Radionuclides	Microbes	Character.	In catalog
✓	✓	✓	✓	✓	–	✓	3 products
✓	–	✓	✓	–	–	–	13 products
–	✓	–	–	✓	–	✓	2 products
–	–	–	–	–	–	✓	None yet
–	–	–	–	–	✓	–	None yet
–	–	–	–	–	–	✓	None yet

Reverse OsmosisNSF/ANSI 58 · 3 products
✓ PFAS✓ Metals✓ Disinfection by-products✓ Radionuclides✓ Water characteristics✓ VOCs
Activated Carbon FiltrationNSF/ANSI 42 · NSF/ANSI 53 · NSF/ANSI 401 · 13 products
✓ Disinfection by-products✓ VOCs✓ PFAS
Ion ExchangeNSF/ANSI 61 · NSF/ANSI 53 · 2 products
✓ Metals✓ Radionuclides✓ Water characteristics
Cation Exchange Water SofteningNSF/ANSI 44 · None yet
✓ Water characteristics
Ultraviolet (UV) DisinfectionNSF/ANSI 55 · None yet
✓ Microbes
Mechanical Sediment FiltrationNSF/ANSI 42 · None yet
✓ Water characteristics

✓ means the technology profile lists the family as potentially relevant. It is not a removal rate; a product still needs a certification that names the contaminant.

Side by side · 2 of 3

Upkeep, standards and limitations

Field	Reverse Osmosis (RO)Semi-permeable membrane separation removing dissolved minerals, heavy metals, and persistent fluorinated chemicals down to 0.0001 microns.	Activated Carbon Filtration (Solid Block / GAC)Highly porous adsorption media targeting chlorine, disinfection byproducts, volatile organic compounds, and organic chemicals.
FormatsWhere it installs	Under-Sink with Dedicated Faucet Countertop Standalone System Commercial Whole-Home (rare, high cost)	Under-Sink In-Line Countertop Gravity Pitcher Faucet Mount Whole-House Main Line
MaintenanceReplacement schedule	Pre-sediment and carbon blocks: Replace every 6 to 12 months RO membrane cartridge: Replace every 24 to 36 months Post-carbon remineralizer: Replace every 12 months	Cartridge replacement every 6 to 12 months based on gallon throughput rating
Published standardsTesting categories named in the profile	NSF/ANSI 58	NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401
LimitationsMust remain visible	Discharges 1 to 3 gallons of brine wastewater for every gallon of purified water produced Removes beneficial healthy dietary minerals (calcium and magnesium); often paired with a remineralization post-filter Requires adequate household line pressure (minimum 40–50 PSI) or an electric booster pump Membrane pores can be fouled by high chlorine or sediment; requires carbon pre-filtration	Ineffective for dissolved inorganic minerals, nitrate, arsenic, or hardness salts Does not reliably remove fluoride or heavy metals without specialized secondary media Carbon bed saturation can lead to chemical desorption and breakthrough if replacement intervals are missed
	Evidence profile 3 catalog products →	Evidence profile 13 catalog products →

FormatsWhere it installs

Reverse Osmosis

Under-Sink with Dedicated Faucet
Countertop Standalone System
Commercial Whole-Home (rare, high cost)

Activated Carbon Filtration

Under-Sink In-Line
Countertop
Gravity Pitcher
Faucet Mount
Whole-House Main Line

MaintenanceReplacement schedule

Reverse Osmosis

Pre-sediment and carbon blocks: Replace every 6 to 12 months
RO membrane cartridge: Replace every 24 to 36 months
Post-carbon remineralizer: Replace every 12 months

Activated Carbon Filtration

Cartridge replacement every 6 to 12 months based on gallon throughput rating

Published standardsTesting categories named in the profile

Reverse OsmosisNSF/ANSI 58

Activated Carbon FiltrationNSF/ANSI 42NSF/ANSI 53NSF/ANSI 401

LimitationsMust remain visible

Reverse Osmosis

Discharges 1 to 3 gallons of brine wastewater for every gallon of purified water produced
Removes beneficial healthy dietary minerals (calcium and magnesium); often paired with a remineralization post-filter
Requires adequate household line pressure (minimum 40–50 PSI) or an electric booster pump
Membrane pores can be fouled by high chlorine or sediment; requires carbon pre-filtration

Activated Carbon Filtration

Ineffective for dissolved inorganic minerals, nitrate, arsenic, or hardness salts
Does not reliably remove fluoride or heavy metals without specialized secondary media
Carbon bed saturation can lead to chemical desorption and breakthrough if replacement intervals are missed

Reverse OsmosisEvidence profile
Activated Carbon FiltrationEvidence profile

Before choosing

Technology is not proof of performance.

A standard defines a testing category. The exact product listing must carry the claim needed for the contaminant and conditions in question.

Certification guide

Sources and methodology

This comparison uses PurityMap’s governed treatment-technology and product records. It does not infer that a contaminant is present, calculate universal removal rates, or rank one method as best.

How treatment relevance is evaluated →

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