Water Knowledge

Iron

Summary: Iron is one of the most common minerals in private wells. It causes orange/brown stains, metallic taste, and clogged fixtures—usually a nuisance rather than a health limit. Testing helps you choose the right treatment so the problem actually goes away.

How iron shows up at home

  • Stains & deposits: Orange or brown on sinks, tubs, toilets, dishwashers, and laundry.
  • Taste & color: Metallic taste; tea-colored water after it sits or after heavy use.
  • Clogging: Reduced flow or fouled filters and appliances.

Where does iron come from?

  • Natural groundwater: Iron dissolves from rock and soil into well water.
  • Corrosion: Steel/iron well components or older piping can contribute iron and rust particles.

Ferrous vs. ferric iron (why it matters)

  • Ferrous (clear-water) iron: Dissolved; water looks clear at the tap but turns orange after standing/aeration. Passes through basic sediment filters.
  • Ferric (red-water) iron: Already oxidized; water looks orange at the tap and can be filtered with the right media.
  • Organic/bacterial iron: Iron bound to organics or influenced by iron bacteria—often slimy with recurring clogs. Needs disinfection plus filtration.

How we test

HealthWaterLab measures iron photometrically. For problem wells, we recommend testing both dissolved and total iron to see how much is particulate. Pair iron with pH, alkalinity, hardness, and (optionally) manganese to guide treatment.

Interpreting results (homeowner version)

  • Very low: Likely no visible issues. Record your baseline.
  • Moderate: Taste/staining likely. Filtration or point-of-use treatment recommended.
  • High: Staining and clogging expected. Plan whole-home iron removal.

Note: Visible symptoms can appear even at modest levels depending on pH and oxygen. Interpret iron alongside other water chemistry.

Treatment that actually works

  • Oxidation + filtration: Aeration, chlorine, or another oxidant converts ferrous to ferric iron so media (e.g., manganese-dioxide blends) can capture it. This is the backbone of whole-home systems.
  • Point-of-use RO: Under-sink reverse osmosis provides low-iron water for drinking/cooking.
  • Address iron bacteria: If present, shock chlorination and ongoing maintenance are needed; otherwise filters re-foul quickly.

Practical homeowner tips

  • Log color/odor/staining patterns with lab results—this helps size equipment.
  • Replace pre-filters on schedule; a clogged filter is a symptom, not a cure.
  • After installing treatment, verify with a follow-up iron test and a quick TDS/conductivity check.

FAQ

Will a simple sediment filter fix iron?

Usually not. Dissolved (ferrous) iron passes through; oxidized (ferric) iron quickly clogs basic filters. Use oxidation + proper media.

Do water softeners remove iron?

They can remove small amounts but foul easily and are not primary iron filters. Use dedicated iron treatment; keep the softener for hardness.

Why does my water turn orange after it sits?

Dissolved ferrous iron oxidizes to ferric iron when exposed to oxygen, creating orange color and particles.

What media work for iron?

Manganese-dioxide based media (and similar catalytic blends) are common after oxidation. Choice depends on pH, iron level, and whether manganese or H₂S are also present.

How do I know if I have iron bacteria?

Slime in toilets/filters, metallic or swampy odors, and rapid re-fouling after filter changes. Disinfection (e.g., shock chlorination) plus maintenance is required.

Is reverse osmosis (RO) only for drinking water?

Yes—RO is typically installed at the kitchen sink for cooking/drinking. Whole-home iron removal uses oxidation + filtration.

What is reverse osmosis (RO)?

Reverse osmosis is an under-sink drinking water system that pushes water through a very fine semi-permeable membrane. The membrane rejects many dissolved contaminants (like arsenic, nitrate/nitrite, lead, copper, and salts), producing low-TDS water for cooking and drinking.

How it works: Pre-filters remove sediment and chlorine → the RO membrane removes dissolved ions → an optional carbon “polishing” filter improves taste → treated water is stored in a small tank and dispensed at a dedicated faucet.

Good to know: RO is point-of-use (kitchen sink), not whole-home; filters/membrane need periodic replacement; some water is sent to drain during operation. If you prefer a little mineral taste, a small remineralization cartridge can be added.

Should I test manganese too?

Often yes. Manganese behaves like iron and can influence media selection and settings.

Can I shock the well myself?

Many homeowners do, but follow local guidance for dosing, contact time, and flushing. Re-test after the system clears to verify results.

How often should I retest?

Annually for private wells, after treatment changes, and any time symptoms return.

Ready to test? Order an iron test (and optional manganese) and get step-by-step sampling instructions at HealthWaterLab.com.