How to Test Your Water (Before You Buy Any Filter)

Every filter purchase should start with a diagnosis. A system certified for PFAS does nothing for iron; a softener does nothing for lead. Here is the testing ladder, cheapest first.

Start with the cheapest test of all: your own palate. Pour tap and filtered side by side, taste both blind if you can, and write down what you notice - it tells you whether your problem is taste, or something a lab needs to name.

Step 1 - City water: read your free report

Every US community water system publishes an annual Consumer Confidence Report (CCR) with detected contaminant levels. Find yours on the EPA's CCR search or your utility's site. Note anything near its limit, plus your system's disinfectant (chlorine vs chloramine - chloramine needs catalytic carbon and more contact time).

Step 2 - Targeted lab tests

For your own tap - which adds your plumbing to the picture - use a state-certified or mail-in lab panel. The standard concerns and rough panel logic: lead (first-draw sample, morning), hardness (a cheap titration kit suffices), PFAS (a few hundred dollars; do it if you're near a known source, on a well, or before buying PFAS treatment), and for wells the EPA's annual list below.

Step 3 - Well water: the annual panel

The EPA does not regulate private wells; testing is the owner's job - more than 43 million Americans in 23 million households. The EPA recommends testing at least annually for coliform bacteria, nitrates, total dissolved solids and pH, plus locally relevant extras (arsenic, radon, VOCs near fuel storage). Your state health department usually lists certified labs and sometimes subsidizes panels.

Step 4 - Match treatment to results

Bring your report to our Filter Finder - or read the two decision guides: RO vs carbon for the tap, and countertop vs whole-house for the bigger call. Test strips have their place (quick hardness and chlorine checks); they are not a basis for a $400 decision.