Water problem
Iron and rust staining
Iron dissolved from rock or from corroding pipe. It is a secondary contaminant, meaning it is regulated for appearance and taste rather than health, but it stains persistently and fouls other equipment.
What you might notice
- Orange or brown staining in sinks, tubs, and toilet cisterns
- Laundry coming out with rust marks
- A metallic taste
- Water that is clear when drawn then discolours after standing
Reading the stain
Colour is diagnostic and it costs nothing to look. Orange and brown staining is iron. Black or very dark brown is usually manganese, which often travels with iron. Blue-green is copper from acidic water, which is a different problem entirely and needs the opposite treatment.
Where the staining appears matters too. Marks below a tap that runs constantly point to something in the supply. Marks in a toilet cistern that sits still for long periods point to something settling out of standing water.
A reddish slime rather than a hard stain indicates iron bacteria, which are living organisms feeding on the iron. That needs shock chlorination of the well rather than filtration alone, and it is worth identifying before buying equipment.
Dissolved or already oxidised
Draw a glass and watch it. If the water is clear coming out of the tap and turns orange over the next few minutes, the iron is dissolved and is oxidising on contact with air. If it is discoloured the moment it leaves the tap, the iron is already a particle.
That distinction decides the treatment. Dissolved iron has to be oxidised before anything can filter it out, so the system needs an oxidation stage. Already oxidised iron can be captured directly by filtration.
Iron is a secondary contaminant, regulated at 0.3 milligrams per litre for appearance and taste rather than for health. Manganese has a secondary standard of 0.05 milligrams per litre and stains at concentrations well below what most people would guess.
Before you buy anything
If you are on municipal water and this started suddenly, call the utility first. Hydrant flushing, a main break, or a change in flow direction stirs up iron that has settled in the mains over years. It usually clears within days and it needs no equipment at all.
If you are on a well, get a test that reports total iron, manganese, and pH, and that distinguishes dissolved from oxidised iron. Sizing a system without that is guesswork, and it is the usual reason an iron filter underperforms.
Clean existing stains after the treatment is running, not before, otherwise you will be doing it twice.
How to confirm it
A well test reports total iron in milligrams per litre. The secondary standard is 0.3 mg/L. Whether the iron is dissolved, already oxidised, or bacterial changes the treatment, and only a test distinguishes them. Water that is clear at first then browns on standing indicates dissolved iron.
The test that settles this is laboratory iron panel, distinguishing dissolved from oxidised iron. We include what we can measure on site in a free water test, and we will tell you plainly when a certified laboratory is the right next step rather than anything we can do at your kitchen tap.
When not to treat it
If the staining started suddenly on city water, call the utility before buying anything. A main break or hydrant flushing stirs up settled iron and clears on its own within days. Installing equipment for a temporary event wastes money.
Treatment options that actually apply
These are the equipment types that address this problem. Each page states what the equipment does not do, so you can rule it out quickly if your situation does not match.
- Iron and manganese removal. Oxidation followed by filtration, sized to the form and concentration of iron present.
- Sediment filters. A mechanical filter that captures sand, silt, rust flakes, and other particles.
- Well water systems. A treatment train assembled around a current laboratory test, in stages.
What none of these will do
- Iron bacteria, which forms slime and needs shock chlorination rather than filtration alone.
- Existing rust stains on fixtures and laundry, which must be cleaned separately.
- Hardness, lead, or nitrates.
Getting it installed
Once a test has confirmed the problem and narrowed the equipment, the practical questions are access, space, and whether anyone's permission is needed. Those are covered on the installation pages, along with what a visit involves and how long it takes.
- Free water testing. 45 to 60 minutes.
- All installation services
- What installation costs
Other water problems
- Hard water
- Chlorine and chloramine taste
- Lead in drinking water
- PFAS
- Sulfur smell
- Sediment and cloudy water
Sources
- Secondary Drinking Water Standards. US Environmental Protection Agency, 2024.
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