State guide, updated 2026-11-14

Rust stains in Florida: well water, sprinklers, pool decks and boats

Short answer: Florida rust stains almost always come from irrigating with well water that carries dissolved iron. UF/IFAS Extension says most Florida well water is high in iron and leaves rust deposits on whatever it touches. Lift the stains with a rust stain remover, a wet dwell and a long rinse, then cut the source with better sprinkler aim, a water test and iron filtration.

Why Florida concrete turns orange

Florida runs on groundwater. The UF/IFAS Florida Well Owner Network says more than 93% of Florida residents rely on groundwater for drinking water, and many homes also run a separate shallow well just for the lawn. That irrigation water is where most of the orange comes from.

The Florida-Friendly Landscaping program at UF/IFAS puts it plainly: most Florida well water is high in iron, the stains often show up when that water is used for irrigation, and high iron can also block drip irrigation lines. The iron is dissolved and invisible when it leaves the pump. Once it lands on a warm driveway, a stucco wall or a white vinyl fence and dries, it reacts with air and leaves a thin orange layer. Every watering cycle adds another layer, which is why the stain follows the exact arc of the sprinkler head.

For scale, the EPA lists reddish or orange staining as the noticeable effect of iron in water at its secondary guideline of 0.3 mg/L. That is a cosmetic guideline, not a health limit, and it is a low number. Water does not need to look rusty coming out of the head to stain a slab over a summer.

Reclaimed water and purple pipe neighborhoods

Many Central Florida subdivisions irrigate with reclaimed water instead of a private well. The Florida Department of Environmental Protection reports that about 1,029 million gallons per day of reclaimed water were put to beneficial use in 2025, and that public access systems irrigated 631,795 residences. Reclaimed water is a different supply with its own quality profile, so do not assume it is the culprit. If you are on reclaimed water and still see orange, check for iron-bearing fertilizer pellets, rusting furniture legs, or a neighbor's well-fed heads spraying across the property line.

What we see here on the Space Coast

SpraySticks is made in Merritt Island, in Brevard County, so these are the stains we look at every week: orange fans across driveways and sidewalks, streaks on painted stucco block walls, rings on pool deck pavers under the screen enclosure, and rust tears running down boat hulls from cleats and rails after a season of salt air.

Not every crust is rust. UF/IFAS notes that coastal wells often carry salt and that hard water leaves white, filmy deposits on plants. A white or gray chalky crust is mineral scale. Orange, tan or reddish brown is iron. Treat the orange; a rust remover is the wrong tool for white scale.

Florida surfaces and what to watch

• Driveways, sidewalks and curbs. The most common job. See the full method in our concrete rust stain guide.
• Painted stucco. Test a hidden patch first. Some paints dull or lighten, and old chalky paint can come away with the stain.
• Pavers and pool decks. Rinse the deck first, work in small sections and keep runoff out of the pool. Never mix with chlorine, bleach or pool chemicals.
• Vinyl siding, soffits and fences. Usually an easy lift. Our vinyl siding guide covers it.
• Boats and trailers. Gelcoat streaks below fittings respond well. Treat the streak, not the whole hull.
• Do not use on travertine, coquina, keystone, limestone or marble. It can etch quarried stone.

How to remove irrigation rust stains

1. Go early. Florida sun dries a slab in minutes. Work in the morning or on a cloudy day so the solution stays wet.
2. Gear up. Chemical-resistant gloves and sealed goggles. Long sleeves if you are spraying overhead on a wall.
3. Soak the plants. Water the grass edge, shrubs and beds next to the work area with plain water first, so the roots and leaves are full of clean water.
4. Wet the surface. Hose down the concrete, stucco or deck before you apply.
5. Apply and keep it wet. Spray the stain evenly. Mist again if any area starts to dry. Follow the label dwell time.
6. Scrub. A stiff nylon brush on concrete, a soft brush on stucco, siding and gelcoat.
7. Rinse long. Flood the area with plain water, then rinse the plants again. Old, dark stains may need a second pass.

For a whole driveway, a pump-up or backpack sprayer is faster than a spray bottle. Use a plastic sprayer, not brass. See rust remover for pump sprayers.

Keep it from coming back

Cleaning without fixing the water means you will be back in a few months. Start with the cheap fixes and work up.

• Aim the heads. Adjust arcs so they water grass and beds, not the driveway, walls or screen enclosure. Swap overspraying rotors for low-angle nozzles near hardscape. Our irrigation rust stain guide goes deeper.
• Test the well. The Florida Department of Health recommends testing private well water every year for coliform bacteria, nitrate, lead and pH, and some county health departments offer testing. Add iron and manganese to that request so you know what you are dealing with.
• Treat the water. The Florida Well Owner Network lists water softeners, iron filters and chemical oxidation among the ways to remove iron. Size any system from a real test result, not a guess.

Which SpraySticks to use in Florida

For the house, driveway, stucco and fences, use the green HOME line. For boats, the blue MARINE line. For trailers, tow vehicles and wheels, the red AUTO line. A spray bottle job takes sticks: one stick per 16 to 24 oz bottle for light stains, two for heavy. A driveway or pool deck job takes gallon pods: one pod per gallon for heavy stains, one per 1.5 gallons for light, and four pods fill a backpack sprayer. Everything ships dry by ground to the lower 48, so you add your own water. Browse the shop.

Safety

Same compound as spinach. Way less friendly than a salad.

Wear gloves and eye protection, keep children and pets off the area until it is rinsed, store sticks and pods sealed and out of reach, and never mix with bleach, chlorine or other cleaners. Read the safety data sheet before your first job. Working in another state? See our pages for Georgia, South Carolina and Texas.

Spinach check: SpraySticks shares a compound with spinach. That does not make it food or gentle. Gloves, eye protection, keep kids and pets away, never mix with bleach, and read the SDS.

Common questions

Why does my Florida sprinkler leave orange stains?

Most Florida irrigation wells pull groundwater that carries dissolved iron. When that water lands on concrete, stucco or a fence and dries in the sun, the iron reacts with air and leaves an orange film that builds with every watering cycle. UF/IFAS Extension notes that most Florida well water is high in iron and can leave rust deposits on anything it touches, even plants.

Does reclaimed water cause rust stains?

Reclaimed water is a different supply from a private well, and its quality depends on your utility. If you are on a reclaimed system and still see orange stains, ask the utility for its water quality report, then look for other sources such as iron in granular fertilizer, metal furniture, or a neighbor's well-fed sprinklers overspraying your property.

Can I use a rust stain remover on my boat?

Yes, on gelcoat and painted fiberglass where rust streaks run down from cleats, rails and fasteners. Rinse the hull first, apply to the streak only, keep it wet, then rinse well and keep runoff out of the water as much as you can. Test a hidden spot first, and replace the rusting hardware or the streaks will come back.

Where can I get my Florida well water tested for iron?

Start with your county health department, since some Florida county health departments offer well testing, or use a NELAP-certified laboratory. Your county UF/IFAS Extension office can point you in the right direction. Ask specifically for iron and manganese, because a basic bacteria panel will not tell you why your driveway is turning orange.