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Water problem — solved

Iron Bacteria in Well Water

A slimy reddish-brown film in the toilet tank, stringy gunk in the pressure tank, or a well that smells swampy after sitting is often iron bacteria — living organisms that feed on dissolved iron. They are not a sewage emergency. They are also not the same job as an air-injection filter sized for clear-water iron. If someone quoted a softener for that slime, they quoted the wrong chemistry.

The problem: slime, not just rust

Iron bacteria colonize wells, pressure tanks, and toilet tanks where iron and oxygen meet. The film is slimy, sometimes iridescent, and it comes back after you scrub if the well keeps feeding it. Health agencies treat typical residential iron bacteria as a nuisance — staining, odor, clogged components — not as the same risk as coliform. You still want a real bacteria panel if the well has never been tested. The slime itself needs oxidation and disinfection that ordinary resin will not do.

The solution: knock it down, then keep it from returning

Shock chlorination of the well can knock the colony back. It is not a cure if the aquifer keeps supplying iron and the organisms. Lasting treatment is usually chemical oxidation (chlorine or peroxide) with contact time, then filtration and carbon polishing so you are not drinking the oxidizer. Air-injection that works for ferrous iron often is not enough once bacteria have slimy hold. We measure iron, look at the tank, and do not hang a softener on slime. Quote after the free well visit.

Root causes

What causes it in NEPA homes

Iron plus oxygen in the well

The organisms need dissolved iron and a little air. Pressure tanks and toilet tanks are favorite rooms.

A well that sits

Seasonal Pocono homes and idle weeks let slime establish. Opening weekend is when people see it.

Not pink Serratia

The bathroom’s pink ring is usually airborne bacteria in soap scum, not well iron. Orange-brown slime in the tank is the iron-bacteria look.

Clear-water iron is a cousin, not a twin

Ferrous iron pours clear and stains orange on fixtures. Iron bacteria adds the slime. Many wells have both. The train has to admit that.

Your options

Ways to fix it

Do not start with a softener

Resin is for hardness. Iron fouls it; slime coats it. An iron-bacteria well needs oxidation first.

Iron & rust stains

Shock, then a continuous oxidation stage

Well disinfection knocks the colony down. Peroxide or chlorine feed with retention and filtration is how it stays down when the aquifer keeps contributing.

Iron filter installation

Treat iron and sulfur in order

Iron bacteria and hydrogen sulfide often travel together in NEPA wells. The panel decides whether one oxidation stage covers both.

Sulfur filters

Good to know

Frequently asked questions

Is iron bacteria dangerous to drink?
At typical well levels it is a nuisance — slime, stains, odor — not the same as an E. coli hit. You should still run a coliform test on an unregulated Pennsylvania well. The slime does not replace that lab.
Will an air-injection iron filter fix the slime?
Sometimes it helps with the iron the bacteria feed on. Established slime often needs a stronger oxidizer and contact time. We look at the tank and the milligrams before we promise an air-injection-only design.
Why does shocking the well not last?
Shock is a knockdown. If iron and the organisms are still in the aquifer, they return. Continuous treatment is the difference between a weekend chore and a fix.
What does treatment cost?
It depends on iron level, whether sulfur is along, and how colonized the well is. We quote after the free test. No prices on this page.