Well water problems and what fixes them

Iron

Signs: rust-colored water, reddish-orange stains, a metallic taste. Dissolved ("clear-water") iron comes out of the tap clear and turns orange-brown when it stands.⁴

What works depends on how much iron you have:⁴

• Water softener: dissolved iron below 5 mg/L, with pH above 6.7.
• Greensand oxidizing filter: iron plus manganese of about 3–10 mg/L.
• Oxidation + filtration (chlorine, permanganate or peroxide, followed by a filter): higher levels, above 10 mg/L. Aeration with a filter may also work (no level given).

Sources give different upper limits: UGA Extension puts oxidizing filters at up to 15 mg/L and pressure aeration with filtration at up to 25 mg/L.⁵ Check the manufacturer's stated maximum for any system you consider.

What doesn't: a softener can't handle iron that is already oxidized (red water); it fouls the resin. Polyphosphate only hides low iron levels and doesn't remove it.⁴

Iron filter guide: the filter we'd look at first

Iron bacteria

Signs: orange or slimy deposits in the toilet tank, orange water, a swampy or musty smell.⁶ They are a nuisance rather than a health risk, but they come back.

What works: shock chlorination of the well, cleaning of the well by a professional, or continuous chlorination with a filter. If you need to shock the well more often than every 6 months, look at other options. What doesn't: filters "will not control populations within the well".⁶

Manganese

Signs: black-brown water, black stains, a bitter metallic taste.⁴ Secondary benchmark 0.05 mg/L; EPA's non-enforceable health advisory is 0.3 mg/L.^{3, 4}

What works: a softener for small amounts, greensand, or oxidation + filtration. Birm media needs a pH of at least 7.5 for manganese and gives variable results. What doesn't: polyphosphate.⁴

Hydrogen sulfide (rotten-egg smell)

Signs: a rotten-egg smell, noticeable at very low levels. If you only smell it in hot water, the cause is often the water heater's magnesium anode rod; replacing it with an aluminum anode is the simple fix.⁷

What works in the whole house:⁷

• Activated carbon at low levels (Penn State: below about 1 mg/L; UGA warns carbon may fail above 0.3 ppm⁸).
• Greensand up to about 2–3 mg/L; aeration up to about 2 mg/L.
• Chlorination + filtration at any level, with about 20 minutes of contact time.

What doesn't: Birm media. Shock chlorination helps only for a while; the smell "will return quickly".⁷

Rotten-egg smell guide

Hardness

Signs: white scale on fixtures and in kettles, soap scum, a shorter water-heater life. Hardness below 7 grains per gallon rarely causes major scaling.⁹ There's no health limit.

What works: a cation-exchange water softener. Keep in mind: a softener is not a purifier. It "will not necessarily remove any of the more serious" contaminants and doesn't remove germs. It adds sodium (about 7.5 mg per quart for each grain per gallon removed) and uses about 50 gallons per regeneration, which goes to your septic system.⁹

Low pH (acidic water)

Signs: blue-green stains from copper pipes, reddish stains from galvanized pipes, pinhole leaks, a metallic taste. EPA's secondary range is pH 6.5–8.5.^{3, 10}

Low pH itself isn't a health problem, but it dissolves metals like copper and lead from plumbing. What works: a calcite or magnesia neutralizing filter, or a soda-ash feed pump for high-flow systems. A neutralizer adds hardness, so it goes before a softener.^{5, 10}

Sediment and cloudy water

What works: a cartridge filter for light loads; a backwashing sand or multimedia filter for heavy loads.^{5, 11} It goes ahead of UV and reverse osmosis.^{1, 25} Keep in mind: it doesn't remove dissolved contaminants, and bacteria can grow in exhausted cartridges. UGA notes that turbidity above 5 NTU can point to bacterial contamination, so test for bacteria too.⁵

Tannins (tea-colored water)

Activated carbon "can also remove tannins".⁸ Special anion "tannin resins" are common in the industry, but we found no extension or agency source that evaluates them, so ask for the manufacturer's data. Color also makes UV disinfection less effective.