Water Softener vs Water Filter: What Each One Removes (Chlorine, Iron, Lead)

By Casey Miller · Updated October 2026

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Quick answer: a water softener doesn’t filter your water. The Minnesota Department of Health (MDH) says softening removes calcium and magnesium (hardness) and can remove copper, iron, manganese and radium, but it doesn’t list chlorine, lead, bacteria, nitrate or PFAS. Those need a filter, and the right one depends on the problem: carbon for chlorine taste and odor, an iron filter for heavy iron or rotten-egg smell, reverse osmosis for many dissolved contaminants in drinking water, and UV for bacteria. Many homes need both: a softener for scale, and a filter for what you drink.

What to buy:

For hard water: a salt-based softener
For drinking water (lead, nitrate and more): an under-sink reverse osmosis system
For both, whole house: a filter and softener combo

How we wrote this: the removal table follows the Minnesota Department of Health’s home water treatment guide, with EPA’s guidance for lead and PFAS filters. We haven’t tested these products ourselves.

What a water softener does, and doesn’t do

A softener runs water through resin beads that swap calcium and magnesium for sodium (or potassium). That stops scale, spots and soap scum; see water softener benefits. MDH says softening is the cheapest option for removing hardness, and lists copper, iron, manganese and radium as other things a softener can remove.

MDH also lists two downsides. Softening with sodium chloride adds sodium to the water, which matters for some people (see is softened water safe to drink). And softening may make water more corrosive, which MDH says may be a health concern if you have copper or lead pipes.

Does a water softener remove chlorine?

No. Chlorine isn’t among the things MDH says a softener removes, and it’s hard on the softener itself: Purolite, a resin maker, says chlorine shortens resin life. On chlorinated city water, a carbon filter installed before the softener removes the chlorine and protects the resin. See our resin guide and filter and softener combos.

What water filters remove

“Water filter” covers several technologies, and each targets different problems. MDH says no single treatment unit removes everything, so you may need more than one.

Carbon filters remove chlorine and chemicals that cause tastes and odors, including hydrogen sulfide. MDH says some are certified for lead, radon, trihalomethanes and volatile organic compounds, and an MDH study found carbon effective at removing PFAS. Carbon doesn’t remove iron or nitrate.
Reverse osmosis (RO) pushes water through a membrane. MDH says it removes a wider variety of contaminants than most options, including lead, arsenic, nitrate, PFAS, sodium and hardness. It’s usually installed under the kitchen sink for drinking water; see softener vs reverse osmosis.
Iron filters (oxidizing media) remove iron, manganese and hydrogen sulfide, and MDH says they’re more effective than other oxidation methods for iron, manganese, arsenic and radium. See water softeners for iron.
UV disinfection kills bacteria and viruses but doesn’t remove chemicals.

Softener vs filter: what each one removes

Problem	Water softener	Carbon filter	Reverse osmosis	Iron filter	UV
Hardness (calcium, magnesium)	Yes	No	Yes	No	No
Chlorine taste and odor	No	Yes	Not on its own*	No	No
Iron	Some	Certified models	Yes	Yes	No
Manganese	Some	No	Yes	Yes	No
Hydrogen sulfide (rotten eggs)	No	Yes	No	Yes	No
Lead	No	Certified models	Yes	No	No
PFAS	No	Yes	Yes	No	No
Nitrate	No	No	Yes	No	No
Arsenic	No	No	Yes	Only with high iron	No
Bacteria and viruses	No	No	Yes	No	Yes
Radium	Yes	No	Yes	Yes	No

From the Minnesota Department of Health’s Home Water Treatment guide (revised March 2024), which lists what each method is “designed to fully or partially remove.” “Some” iron and manganese: a softener handles only dissolved iron within its rating. *MDH doesn’t list chlorine for RO, but most under-sink RO systems include carbon stages; both RO systems we’ve covered list chlorine reduction. Always check a product’s certification for the specific contaminant.

Softener, filter or both?

Tick the problems you have to see what treats them.

Tick at least one problem to see what treats it.

How it works: each problem maps to the treatments MDH lists for it, with EPA’s certification guidance for lead and PFAS. Test your water first; MDH says most Minnesotans don’t need home water treatment to protect their health.

When you need both

Hard, chlorinated city water: a carbon filter, then the softener. The carbon removes chlorine and protects the resin.
Hard well water with iron or a rotten-egg smell: an iron filter, then the softener. See our well water guide.
Hard water plus a drinking-water concern (lead, nitrate, PFAS): a whole-house softener and an RO system at the kitchen sink.

Our filter and softener combo guide covers the right order and complete systems.

A special note on lead

For lead, EPA’s consumer tool points to point-of-use and pitcher filters certified to NSF/ANSI 53 and NSF/ANSI 42 (Class I particulate) to reduce lead to 5 parts per billion or less. EPA notes that homes may have plumbing that contains lead, so a filter at the tap you drink from treats water after it has passed through those pipes. A softener won’t remove lead, and MDH says softening may make water more corrosive to lead pipes.

What to buy

For hard water

AFWFilters Fleck 5600SXT 48,000-grain softener

A two-tank salt-based softener on the widely used Fleck 5600SXT valve, with 1.5 cubic feet of resin. It removes hardness but doesn’t filter; add carbon in front of it on chlorinated water.

Good to know: size yours first, and compare other softeners in our best water softeners guide.

Check price on Amazon

For drinking water

iSpring RCC7AK reverse osmosis system

A 6-stage under-sink RO system with a storage tank and a remineralization stage. iSpring says the whole system is certified to NSF/ANSI 58.

Reductions listed: lead, PFAS, chlorine, fluoride, copper, barium and TDS, among others (listing)
Capacity: up to 75 gallons a day (listing)

Good to know: check iSpring’s performance data sheet for the specific contaminants it’s certified to reduce. For lead, EPA’s tool also lists certified pitcher and faucet filters.

Check price on Amazon

Frequently asked questions

Do water softeners filter water?

No. A softener exchanges hardness minerals for sodium or potassium. MDH lists calcium, magnesium, copper, iron, manganese and radium as what a softener can remove; chlorine, lead, bacteria and nitrate need other treatment.

Does a water softener remove lead?

No. For lead, use a filter certified to NSF/ANSI 53 for lead reduction, or an RO system certified for lead, at the tap you drink from.

Should I get a water softener or a water filter?

Test your water first. If the problem is scale and spots, a softener. If it’s taste, odor or a specific contaminant, the filter that treats it. If you have both, you need both.

Do I need a filter on city water?

Not always. Public water systems must meet Safe Drinking Water Act standards, and MDH suggests reading your system’s annual Consumer Confidence Report to learn about your water. Many people add carbon for chlorine taste, or a certified filter for lead from old pipes.

Does a whole-house filter soften water?

A carbon or sediment filter doesn’t remove hardness. For that, you need a softener, or a salt-free conditioner that reduces scale without removing hardness.

Related guides

Sources

Minnesota Department of Health, Home Water Treatment (revised March 29, 2024), and Water Treatment Using Carbon Filters (GAC) (August 2018).
U.S. EPA, Consumer Tool for Identifying Point-of-Use and Pitcher Filters Certified to Reduce Lead in Drinking Water (updated January 2026) and Reducing PFAS in Your Drinking Water with a Home Filter.
Purolite (Ecolab), Factors That Affect Softening Resin Performance and Life.
Amazon listings for the AFWFilters softener and iSpring RCC7AK, checked October 2026.