Orange stains
Often points toward iron, but testing should confirm iron, manganese, pH, hardness, and related chemistry.
Symptoms
Use symptoms as clues, then verify with testing.
A smell or stain can narrow the search, but it should not be the only reason you buy a filter.
Rotten egg smell
Often associated with hydrogen sulfide or bacteria-related issues; treatment depends on source and severity.
Cloudy water
Can be sediment, air, or chemistry. Let the timing and a sample test guide next steps.
Salty taste
Can involve sodium, chloride, softener issues, or intrusion concerns depending on location.
Black specks
Can come from manganese, carbon fines, rubber parts, or well/plumbing debris.