Choose the symptom that matches what you’re seeing or smelling. This tool walks the same path every time — symptom → what to test for → treatment category — so you test before you buy. It doesn’t diagnose your water; only a certified lab result does that.
Select a symptom above to see what it’s usually associated with, what to test for, and the treatment category that typically applies.
Orange stains
Often associated withDissolved iron — sometimes alongside iron-related bacteria — that turns reddish-orange once it contacts air.
What to test forTotal iron, pH, and manganese, from a certified lab sample of untreated water.
Treatment categoryOxidation/filtration (commonly an iron filter), sized to the iron form and concentration your test reveals.
Rotten-egg smell
Often associated withHydrogen sulfide gas, usually produced by naturally occurring sulfur bacteria in the well, plumbing, or water heater.
What to test forHydrogen sulfide, sulfate, and pH — and whether the smell is well-wide or limited to hot water only.
Treatment categoryAeration, oxidation, or activated carbon filtration, chosen by concentration and where the odor is coming from.
Black stains
Often associated withManganese, sediment, corrosion products, or deteriorating fixture and gasket materials.
What to test forManganese, iron, and pH. Photograph the stain first and note whether it wipes away.
Treatment categoryManganese-rated filtration — sized only after a lab result confirms the source, since fixture wear needs a different fix than water chemistry.
Hard-water scale
Often associated withDissolved calcium and magnesium — water hardness — showing up as white mineral scale, soap that won’t lather, or spotting.
What to test forHardness, reported as mg/L as CaCO₃ or grains per gallon (gpg). That number is the useful starting point.
Treatment categoryIon-exchange softening — a different fix than an iron filter, even though the two are often confused.
Cloudy water
Often associated withTrapped air (fill a clear glass and watch — cloudiness that clears from the bottom upward is usually just air) or suspended sediment and turbidity if it doesn’t clear.
What to test forTurbidity, plus a general sediment check. Don’t use appearance alone to decide the water is safe.
Treatment categorySediment filtration if particulate matter is confirmed; treat anything that persists or recurs as a water-quality investigation, not a filter purchase.
I have water-test results
Next stepSkip the guesswork — take your lab report straight to the Water Test Interpreter. It’s a checklist for turning raw numbers (with their units) into a treatment category, without over- or under-reading a single result.
New or suddenly changed symptom? Especially after flooding, well work, pressure loss, or nearby contamination, contact a certified laboratory and your local health or environmental authority directly — don’t wait on this tool. It’s educational and doesn’t replace testing or professional evaluation.
Authoritative starting points