Why does my water look clear but turn orange after sitting?

That's ferrous iron (clear water iron) — dissolved iron that's invisible when drawn but oxidizes into rust-colored particles once exposed to air. It's the most common type of iron problem in well water.

What causes slimy reddish deposits and a swampy smell in my toilet tank?

That's a sign of bacterial iron — microorganisms that feed on iron in the water. Shock chlorination kills the bacteria, and an oxidizing filter afterward prevents it from coming back.

Will a water softener fix iron in my well water?

A standard ion exchange water softener can remove low levels of dissolved ferrous iron along with hardness minerals, but it's only effective for iron under about 3 mg/L. Higher levels need an oxidizing/air injection iron filter instead.

What iron level in well water requires treatment?

Iron below 0.3 mg/L meets the EPA's aesthetic secondary standard and needs no treatment. From 0.3-1 mg/L you may see light staining; 1-3 mg/L is noticeable enough to need an oxidizing filter; above 3 mg/L requires an air injection iron filter, and 10+ mg/L needs a full chemical oxidation system.

What's the difference between ferrous and ferric iron in well water?

Ferrous iron (clear water iron) is dissolved and invisible until it oxidizes after exposure to air. Ferric iron (red water iron) is already oxidized and visible as reddish-brown particles or sediment, often from old iron pipes as well as the aquifer — a sediment filter addresses this type.

Well Water Testing When Buying or Selling a Home

Category: Well Water

Updated: June 2026

Site: MyWellWaterTest.com

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If a home has a private well, water testing isn't just a good idea before you buy — for many loan types, it's mandatory. FHA and VA loans require a potability test before closing in nearly all cases, and many conventional lenders require one too, particularly if the property is in a county with known groundwater contamination issues (nitrates from agricultural runoff, arsenic in bedrock areas, etc.).

What Gets Tested for a Real Estate Transaction

Standard lender-required panels typically test for total coliform bacteria and E. coli at minimum — this is the baseline safety test almost every loan type requires. Many lenders also require nitrate and nitrite testing, especially in agricultural regions. Beyond the minimum, buyers often add lead, arsenic, and a general water quality panel (hardness, iron, pH, TDS) at their own expense, since the lender-required test alone won't catch everything worth knowing about before you own the property.

Who Pays, and Who Orders the Test

This is negotiable and usually spelled out in the purchase agreement, but the buyer typically orders and pays for the test, using a certified lab (not a DIY kit — lenders require results from an accredited laboratory, not an at-home test strip). Turnaround is usually 3-5 business days for bacteria, longer for a full chemical panel.

What Happens If the Test Fails

A failed bacteria test doesn't necessarily kill the deal — shock chlorination followed by a retest often resolves coliform bacteria issues, and many purchase agreements include a clause allowing the seller to treat and retest before closing. Chemical contamination (arsenic, nitrates above the safe threshold) is a more serious issue and typically requires a treatment system to be installed and verified before a lender will clear the loan, which can affect closing timelines and who is responsible for the cost.

For Sellers

If you know your well hasn't been tested recently, testing before listing can prevent a surprise that delays closing. A clean, recent test result is also a selling point buyers increasingly ask for up front.