Iron. It comes up out of the ground dissolved, which is why the water looks perfectly clear at the tap and then leaves orange behind.
The moment it meets air it oxidises and drops out of solution. That’s the stain in the sink, the ring in the toilet, the rust colour on white laundry.
It’s common in wells across Sarasota, Charlotte and DeSoto County, and it usually turns up alongside hardness and sometimes sulfur.
Not every stain is iron though, and the colour tells you which problem you’ve got.
Orange or brown is dissolved iron. Black or dark brown points at manganese, which behaves similarly but needs different media. A reddish slime rather than a hard stain suggests iron bacteria, which is a living organism rather than a mineral and won’t respond to the same treatment.
Getting that identification right first is what stops you buying the wrong equipment, which is what the free water test is for.
How Iron Gets Removed
The equipment depends on how much iron is in the water and what form it’s in.
Low levels can sometimes go through a softener, which will pull some iron out along with the hardness. Higher levels foul the resin and shorten the softener’s life badly.
Above that, iron gets its own stage in front of the softener. Oxidation and filtration, sized to the reading.
Iron bacteria is a different job again, and it usually needs the well itself treated rather than just the water coming into the house.
A free test tells us which of the three you’re dealing with before anybody quotes equipment.