At‑a‑Glance

• Aesthetic threshold: 0.05 mg/L—above this, staining and off‑taste are likely.
• Health advisory: 0.3 mg/L (non‑enforceable, protective guidance; infants are more sensitive).
• Manganese often accompanies iron and sometimes hydrogen sulfide; chemistry and speciation (dissolved vs. particulate) determine the fix.
• Reliable treatments: oxidation + filtration for whole‑house control; reverse osmosis (RO) for drinking water at the sink.
• Test annually, and always test before water is used for infant formula.

What Is Manganese & Why It’s in Wells

Manganese (chemical symbol Mn) is a naturally occurring element found in rock and soil. In low‑oxygen groundwater, manganese dissolves as Mn(II) and travels with the water you pump from your well. Once exposed to oxygen or oxidants (air, chlorine, peroxide), dissolved manganese converts to solid Mn(IV)—the black particles that stain fixtures and laundry.

Because groundwater chemistry varies by aquifer, your well can show very different manganese behavior than a neighbor’s. That’s why a lab test—not appearance alone—should guide treatment.

Health & Aesthetic Guidance

• Aesthetic guideline (SMCL): 0.05 mg/L. Above this level, water commonly discolors and stains. Households often treat for convenience and appliance protection.
• Health advisory (lifetime): 0.3 mg/L. This non‑enforceable guidance is protective of neurological health; infants and very young children are more sensitive to manganese exposure.
• Infant formula: If manganese approaches or exceeds ~0.3 mg/L, use alternate water (bottled or RO‑treated) for mixing formula until treatment is in place.

Manganese is not readily absorbed through skin; bathing and showering are not major exposure routes. The priority is drinking and cooking water.

Testing: What, When, and How

When to Test

• Baseline: If you haven’t tested in the past year, order a panel that includes manganese, iron, hardness, pH, TDS, and (if possible) ORP.
• Annually: Re‑test to catch changes from rainfall, drought, or well maintenance.
• Before infant use: Test prior to using tap water for formula; re‑test if any changes in taste/odor/staining appear.

How to Sample

1. Use a state‑certified lab and their bottles; follow instructions for preservation and holding time.
2. Decide your sampling point:
   • Whole‑home performance: sample after your full‑house treatment.
   • Drinking water: sample at the kitchen tap, after any under‑sink RO if present.
3. Record odors (e.g., rotten‑egg smell), discoloration, and any recent shock‑chlorination.

Interpreting Results

Speciation matters: If lab/observations suggest particulate (black) manganese, you need filtration. If dissolved Mn(II) dominates, oxidation + filtration is the reliable path; ion exchange is a limited helper at low levels.

Treatment Roadmap

A) Fastest Health Protection: Reverse Osmosis (RO) at the Kitchen Sink

Under‑sink RO is a proven point‑of‑use solution that reliably reduces dissolved metals, including manganese. It’s quick to install, produces excellent‑tasting water, and directly protects what you drink and cook with.

See RO Pick (5‑Stage, 50 GPD)

B) Whole‑House Control: Oxidation + Catalytic Filtration

The most consistent whole‑home fix for manganese (and iron) is air‑injection oxidation (AIO) paired with a manganese‑dioxide–based catalytic media (e.g., Katalox Light). The air pocket oxidizes dissolved metals; the media catalyzes conversion and captures the solids, then backwashes to clean itself.

• Use cases: Light to moderate manganese and iron, with or without mild H₂S.
• Advantages: Salt‑free for metals, automated backwash, reliable stain control.

AIO + Katalox System    Air‑Injection Oxidizing Filter

C) If Hydrogen Sulfide Is Present or Levels Are High

For tougher water (pronounced rotten‑egg odor or higher manganese), add a small oxidant feed (chlorine or hydrogen peroxide) and a retention tank for contact time before the catalytic filter. This accelerates conversion of Mn(II) to filterable solids and neutralizes H₂S.

Chemical Metering Pump    Retention Tank

D) Where Water Softeners Fit

Ion‑exchange softeners excel at hardness removal and can help with small amounts of dissolved manganese, but they do not filter particulates and can foul if manganese oxidizes upstream. In most designs, the softener sits after oxidation/filtration to protect resin and deliver soft water house‑wide.

High‑Efficiency Softener

Verified Product Picks (WaterSoftenerPlus.com)

The links below point to product pages on WaterSoftenerPlus.com and were checked as reachable on Oct 20, 2025.

Helpful Sizing Tools

• Water Softener Sizing Chart
• Reverse Osmosis Sizing Calculator

Sizing & System Layout

Sizing Principles

• Match media volume to chemistry and flow: Undersized filters plug quickly; oversized units may backwash poorly. Use the vendor’s charts and your lab report.
• Mind backwash rates: Catalytic MnO₂ media require adequate GPM to lift and scour the bed. Check plumbing size and pressure.
• Consider contact time: If using chemical feed, add a retention tank so oxidants fully convert Mn(II) before filtration.

Recommended Plumbing Order

Well ➝ Pressure Tank ➝ (Optional) Oxidant Feed ➝ Retention Tank ➝ AIO/Catalytic Filter ➝ (Optional) Carbon ➝ Water Softener ➝ House
Kitchen Sink ➝ Under‑Sink RO for drinking/ice

Ongoing Maintenance

• AIO/catalytic filters: Follow the recommended backwash schedule; increase frequency if you see pressure drop or faster staining return.
• Chemical‑feed systems: Keep solution tanks clean; verify dosage and replace injector components per the manual.
• Softeners: Use high‑purity salt; periodically sanitize the brine tank; consider a resin cleaner if iron/manganese are present.
• RO systems: Replace sediment/carbon prefilters on schedule; check TDS reduction; replace the membrane per manufacturer guidance.
• Re‑testing: Keep an annual schedule; re‑test anytime taste, odor, or staining patterns change notably.

FAQs

Will a standard water softener fix manganese by itself?

Not reliably. A softener can help with small amounts of dissolved Mn(II) but won’t filter particulates and may foul if manganese oxidizes in the resin. Use oxidation + filtration first, then a softener for hardness.

Is showering in manganese‑containing water safe?

Manganese is poorly absorbed through skin. The main concern is ingestion, particularly for infants. Prioritize RO at the kitchen sink for beverages and formula, and implement whole‑house control to stop staining.

How do I know if I need chemical feed?

If you have strong sulfur odor, higher manganese, or stubborn staining, a metering pump + retention tank before the catalytic filter often yields more complete conversion and capture.

What causes “black water” after shocking my well?

Chlorination oxidized clear Mn(II) into black Mn(IV) solids. That’s expected chemistry—and a sign that oxidation + filtration is the right long‑term fix.

Can I start with RO only?

Yes. RO at the sink is the fastest health safeguard. You can add whole‑house oxidation/filtration later to stop stains and protect appliances.

Step‑by‑Step Action Plan

1. Order a lab test that includes manganese, iron, hardness, pH, TDS (and note any H₂S odor).
2. Protect drinking water now with an under‑sink RO at the kitchen—especially if an infant will use the water.
3. Pick a whole‑house strategy based on results:
   • Light–moderate Mn/Fe: AIO + catalytic media (Katalox Light style).
   • High Mn and/or H₂S: Chemical feed ➝ retention ➝ catalytic filter; optional carbon polish.
   • Add a softener after filtration if hardness is present.
4. Size it correctly using the vendor’s charts and your peak household flow.
5. Install and verify with post‑install testing; adjust backwash frequency and oxidant dosage as needed.