How to Deal With Iron Stains From Well Water
Reddish-brown staining on sinks, tubs and laundry is the signature of iron in well water. The right fix depends on the form of iron and whether iron bacteria are present.
Quick Answer
Reddish-brown or orange staining is caused by iron; dark brown/black usually indicates manganese. These are aesthetic (staining and taste) issues under EPA secondary standards, not health limits. The effective treatment depends on whether the iron is dissolved (clear-water) or oxidized (red-water), the concentration, the pH, and whether slimy iron bacteria are present — all of which a test reveals.
Common causes
- Dissolved ferrous iron that oxidizes and stains on contact with air and surfaces.
- Oxidized ferric iron particles carried in the water.
- Iron bacteria, which create reddish slime and can worsen staining and odor.
- Manganese, which produces darker black/brown stains.
Treatment depends on testing
Have the water tested for iron, manganese, pH, and (if slime is present) iron bacteria. Oxidizing filters, aeration or chemical oxidation followed by filtration, and in some low-level cases water softeners are all used, but the correct choice follows the numbers. Over- or under-sizing treatment is a common and costly mistake.
Removing existing stains
Frequently asked questions
- Does a water softener remove iron?
- A softener can remove modest levels of dissolved iron, but it is not designed as a primary iron-removal system and can be fouled by higher iron or by oxidized iron. For meaningful iron, a dedicated iron filter sized to your test results is usually the better choice.
Sources & references
- Secondary Drinking Water Standards: Guidance for Nuisance Chemicals — US EPA, accessed October 12, 2026
- Hardness of Water — USGS, accessed October 12, 2026
This guide is documentary research and general information, not a laboratory analysis or professional assessment of your specific well. See our disclaimer.