What Iron Does to Your Water and Home
Dissolved iron is invisible when it leaves your well — then it hits air and oxidizes into the reddish-brown particles behind iron staining: orange rings in toilets, rust-coloured laundry, metallic-tasting water, and brown slime in toilet tanks. It's one of the most common complaints from Ontario well owners, and unlike hardness, it doesn't take high concentrations to be miserable — even 0.3 ppm (the aesthetic guideline) stains fixtures.
Iron also destroys equipment it touches. It fouls water softener resin, coats UV sleeves so disinfection fails, and feeds iron bacteria that create rotten-egg-adjacent odours and slimy biofilm. That's why iron usually has to come out first, before everything downstream.
Types of Iron Filters
The right filter depends on your iron concentration, pH, and whether sulfur or iron bacteria are present — all things a water test reveals. The main approaches:
- Air Induction Oxidation (AIO): The most common whole-home solution. The tank holds a pocket of compressed air; as water flows through, iron oxidizes into filterable particles trapped in catalytic media that backwashes itself clean. Handles iron up to ~5 ppm plus sulfur smell in one unit. No chemicals, low maintenance.
- Birm media filters: A catalytic media that accelerates iron oxidation using the water's own dissolved oxygen. Simple and chemical-free, but needs decent pH (above ~6.8) and dissolved oxygen to work — your dealer should verify both.
- Greensand / catalytic carbon: Manganese-coated media that oxidizes and filters iron in one pass. Effective for higher iron or combined iron + manganese, but the media eventually needs regeneration or replacement.
- Chlorine or peroxide injection: For heavy iron (above ~5 ppm), iron bacteria slime, or iron plus sulfur together. A feed pump injects oxidizer ahead of a retention tank and filter. More moving parts, but it handles the worst water.
What Installation Involves
An iron filter installs on the main line where water enters the house — before the softener and UV system, never after. A typical install takes 3–5 hours: cutting in the tank with a bypass loop, connecting the drain line for backwash cycles, and setting the backwash schedule. AIO and media filters need a drain that can handle the backwash flow; injection systems also need space for the chemical tank and a power outlet for the feed pump.
Order matters in a treatment train: iron/sulfur filter → softener → UV. Getting this sequence wrong is one of the most expensive mistakes in well treatment — a softener installed upstream of iron filtration will foul within a year or two.
Iron Filter Cost in Ontario
A professionally installed whole-home iron filter typically runs $1,800–$3,500 in Ontario, depending on the technology, iron levels, and plumbing complexity. AIO systems sit in the middle of that range; injection systems with retention tanks run higher. Ongoing costs are low: periodic media replacement every 5–10 years for most systems, plus chlorine or peroxide for injection setups.
A full treatment train for a well with iron, hardness, and sulfur — iron filter plus softener — commonly lands around $3,500–$6,000 installed. It's a significant investment, but compare it against replacing a fouled softener, a scaled-up water heater, and ten years of ruined laundry.