Well water that tastes metallic

Several different problems produce this same symptom, and they need completely different fixes. Work down the list — each one names the check that rules it in or out.

1. 1

   Iron

   The most common cause by a wide margin. Iron is detectable by taste from around 0.3 mg/L — the same threshold at which it starts staining — so taste and stains usually arrive together.

   How to tell
   Orange or rust staining on fixtures and laundry, and water that yellows in a glass over half an hour.

2. 2

   Manganese

   Tastes metallic and slightly bitter. Frequently found alongside iron, and often blamed on iron because iron is the better-known problem.

   How to tell
   Black or dark brown specks and staining rather than orange. Specks smear brown-black when rubbed.

3. 3

   Copper from acidic water

   Low-pH water dissolving your own copper plumbing. The taste is sharp and distinctly metallic, and is usually strongest first thing in the morning when water has sat in the pipes overnight.

   How to tell
   Blue-green staining in sinks and tubs, plus a pH reading below 6.5. Taste is worst on the first draw and fades after running the tap.

4. 4

   Zinc from galvanised pipe

   Galvanised steel plumbing shedding its zinc coating as it ages. Produces a metallic taste without the characteristic staining of the other three.

   How to tell
   Older galvanised plumbing, a metallic taste with no coloured staining, and often a gradual loss of water pressure as the pipes scale internally.

A full metals panel settles this definitively and is worth doing before you spend money on equipment. But you can usually get to the right answer first with observation, which tells you what to ask the lab for.

The key question is what else you are seeing, because a metallic taste on its own is ambiguous and every metal here has a distinct signature elsewhere in the house.

• Metallic taste plus orange staining — iron.
• Metallic taste plus black specks or grey-brown laundry marks — manganese.
• Metallic taste plus blue-green staining, worst on the first draw — copper, from acidic water.
• Metallic taste with no staining, in a house with galvanised pipe — zinc.
• Metallic taste that appeared suddenly with no other change — test for bacteria too; a change in the well is worth ruling out.

Put your results in context→

This distinction decides whether you are buying water treatment or plumbing work, so it is worth five minutes.

Take a glass from a tap that has not been used overnight and taste it. Then run that tap for three minutes and taste again. If the metallic taste is strong on the first draw and largely gone after running, the metal is coming from your plumbing — copper or zinc — because the water sitting in the pipe had hours of contact time.

If the taste is the same before and after, the metal is in the water arriving from the well, which points at iron or manganese. Confirming at an outside spigot upstream of any treatment equipment makes this more certain still.

Each metal has its own answer, and equipment for one does nothing for another. This is the most common way people waste money on well water: buying a softener because it is the well-known product, when the actual problem was pH.

• Iron up to 3 mg/L or manganese up to 0.3 mg/L — a softener handles it with hardness.
• Iron or manganese above those — an oxidising filter ahead of the softener.
• Copper from acidic water — an acid neutraliser. Treating the pH stops the pipes dissolving; nothing else will.
• Zinc from galvanised pipe — the pipe is at the end of its life. Filtration is a stopgap; repiping is the fix.
• Any of these, for drinking water only — reverse osmosis at one tap is a quick, cheap improvement while you decide on whole-house treatment.

If this turns out to be the cause, here is where the equipment sits in the treatment train. Order matters — each stage protects the one after it.

1. 1
   Acid neutraliserBefore any oxidising filterRaises pH out of the corrosive range. It must come before iron filtration because oxidising media barely works below pH 7.
2. 2
   Iron / manganese / sulfur filterBefore the softenerRemoves iron, manganese and hydrogen sulfide by oxidation. Sits ahead of the softener because iron fouls softener resin and voids most warranties.
3. 3
   Water softenerAfter iron removalIon-exchanges calcium and magnesium for sodium. Handles hardness only — it is not a filter, and it is not a purifier.

Enter your test results for a train built around your water→