Problems guides

Symptom first, equipment second

Almost every wasted water-treatment purchase starts the same way: a symptom is described to a salesperson, and a system is sold before anyone tests the water. Hardness, iron, sulfur, sediment and bacteria each need a different test and a different fix, and two of them can look identical in the shower.

Symptom	Likely cause	Test that proves it	What fixes it
White scale on fixtures, soap won't lather	Hardness (calcium, magnesium)	Hardness test, grains per gallon	Ion-exchange softener
Orange or brown stains, metallic taste	Iron (ferrous or ferric), manganese	Iron and manganese lab test	Oxidation + filtration; softener only for low iron
Rotten-egg smell, worse on hot water	Hydrogen sulfide, or bacteria in the heater	Sulfur test; coliform test	Aeration or catalytic carbon; heater sanitising
Cloudy or gritty water	Sediment, turbidity	Turbidity and sediment test	Sediment filter, 5–20 micron
Blue-green stains, metallic taste	Low pH, corrosive water	pH and alkalinity	Acid neutraliser
Stomach illness after drinking	Coliform bacteria, nitrate	Lab bacteria and nitrate test	Disinfection, UV, RO for nitrate

Hardness: the one you can measure at home

Hardness is reported in grains per gallon (gpg) or milligrams per litre as calcium carbonate. Under 3 gpg is soft, 3–7 is moderately hard, 7–10 is hard, and above 10 is very hard. A $15 titration kit is accurate enough to size a softener; a strip is accurate enough to decide whether you need one at all.

Municipal suppliers publish hardness in the annual water quality report, but the number at your tap can differ after blending or seasonal source changes. Test at the tap, and test both hot and cold if you have a softener already — a failed unit shows up as hard hot water with soft cold.

Iron: the reason softeners get blamed

Ferrous iron is dissolved and clear; it oxidises to ferric iron on contact with air and turns brown. A softener can handle small amounts — roughly up to 2–3 ppm in many residential units — but higher iron fouls the resin and the unit stops softening. The fix is oxidation (air, chlorine or ozone) followed by filtration, then softening if hardness is also a problem.

Manganese behaves similarly at lower concentrations and stains black rather than orange. If either is above the softener's limit, the order of equipment changes: iron removal first, softener second.

Sulfur and bacteria: the health line

Hydrogen sulfide is an odour problem; coliform bacteria are a health problem, and only a lab test separates them. A sulfur smell that appears only on hot water usually means bacteria in the water heater, not in the well — sanitising the heater is the fix, not a new filter. A smell on cold water at every tap points to the supply.

Nitrate has no taste and no smell. It comes from fertiliser, septic systems and manure, and it is the one contaminant where a cheap DIY strip is worth using monthly if you have a private well near agricultural land. Above 10 mg/L as nitrogen, do not drink the water and do not mix formula with it; a lab confirmation and a reverse-osmosis unit at the tap are the minimum response.

Start with the well water testing guide if you are on a private supply, and the hard water symptoms guide if the complaint is scale rather than stains. The systems hub explains what each piece of equipment removes; the cost hub carries the installed prices.

How often should I test well water?

Once a year for bacteria and nitrate, and every 3–5 years for the full panel (pH, hardness, iron, manganese, arsenic, lead). Test sooner if the water changes colour, taste or smell, or if a neighbour's well tests positive for bacteria.

Can a softener remove bacteria?

No. A softener is an ion-exchange unit, not a disinfectant, and bacteria can multiply in the resin bed. Bacteria need disinfection and usually a UV unit after filtration.

Is hard water dangerous?

No — it is a nuisance, not a health risk. The costs are scale in appliances, extra soap and shorter water-heater life, which is why the decision is economic rather than medical.