How We Test

Our goal is to predict how a filter will perform in your situation—not in a vacuum. That starts with your source water (city CCR or well test), then moves through certified performance data, hands‑on measurements, and lifecycle modeling for cost and waste.

Step 1: Map your water profile

City water: We parse your Consumer Confidence Report for regulated contaminants, typical chlorine/chloramine treatment, hardness, and seasonal notes. We layer in state or city advisories when relevant.
Wells: We recommend a certified lab panel based on local geology and known risks (e.g., arsenic, nitrates, manganese, PFAS). We review detection limits and sampling methods to avoid false comfort.

Step 2: Screen by verified certifications

We match your contaminants to relevant standards (e.g., NSF/ANSI 42 for chlorine taste/odor, 53 for lead/cysts, 58 for RO, 401 for emerging compounds, P231 for microbiological purifiers, P473/P477 for PFAS). We confirm claims against official listings and note listing IDs when available.
We record rated capacity, flow rate, pressure range, and reduction percentages at the tested flow—because performance depends on conditions.

Step 3: Hands‑on evaluation (when applicable)

Flow and pressure: We measure actual flow (GPM/LPM) and pressure drop across cartridges at common household pressures.
Taste and odor: We perform basic sensory checks and, when feasible, simple blinded triangle tests for chlorine removal and flavor improvement.
Installation and renter‑friendliness: We assess tools required, counter/under‑sink space, and reversibility (no‑drill and quick‑connect options prioritized for rentals and RVs).
Noise and ergonomics: We note pump/RO noise, faucet feel, and cartridge change ergonomics.

Step 4: Lifecycle cost modeling

True cost‑per‑gallon: We combine purchase price, certified capacity, realistic usage, and replacement schedules over 1–5 years.
Replacement cadence: We model both time‑based and volume‑based changes; we prefer systems that maintain performance until end‑of‑life without sharp drop‑offs.
Parts availability: We check that replacement cartridges/housings are broadly available.

Step 5: Waste footprint modeling

Plastic mass per gallon: We estimate total plastic for cartridges over the modeled period and amortize reusable housings.
RO recovery ratio and water use: We measure or use rated recovery to estimate reject water per gallon of product water.
End‑of‑life: We note recycling options and take‑back programs, if any.

Scoring framework (weights may vary by category)

Certified contaminant reduction: 35–45%
Taste, odor, and user experience (including flow impact): 15–20%
Installation and maintenance burden (owner vs. renter): 10–15%
True cost‑per‑gallon (1–5 year view): 15–20%
Waste footprint (plastic mass, RO recovery): 10–15%

Transparency and limits

We publish assumptions (household size, daily gallons, feed water ranges) and sensitivity analyses where they materially change rankings.
We do not treat TDS meters as proof of safety; TDS is a proxy for dissolved solids, not specific contaminants. For health‑critical claims (e.g., lead/PFAS), we rely on certifications or accredited lab results.
If a product lacks relevant certifications, we’ll say so and explain what any third‑party or in‑house testing can and cannot prove.

Updates and re‑testing

We revisit picks when certifications change, models are revised, or new data emerges. For seasonal or advisory‑driven topics, we post interim updates with clear timestamps.

Replicability

Our calculators and test notes summarize formulas (e.g., cost‑per‑gallon, cartridge mass per gallon, RO recovery). When possible, we share templates so you can plug in your own usage and pricing.

Bottom line

We favor systems with verified performance for your contaminants, predictable maintenance, and lower waste. When in doubt, we’ll show the trade‑offs so you can choose confidently for your home, well, RV, or trail.