How we rate
Every score out of 10 comes from four weighted factors.
40% — Certified removal
Only independent certifications (NSF, WQA, IAPMO) count fully. Lab-tested claims count partially; marketing claims count zero.
25% — True cost
Upfront price plus replacement filters over 5 years.
20% — Ease of use
Installation, filter changes, speed and space.
15% — Reliability
Warranty, build quality and owner feedback.