Water · Best-of

Best Reverse Osmosis System

Reverse osmosis filters at the membrane level, covering the widest range of dissolved contaminants. The tradeoffs are wastewater and cost per gallon. We score RO systems on certified reduction, running cost, and how efficiently they use water.

How we score: We rank reverse-osmosis-class systems by composite score, which weights certified contaminant reduction, cost per gallon, and wastewater ratio.

1. 17.2

   AquaTru Classic Countertop RO

   The AquaTru Classic Countertop RO is a ro water filter. It is third-party certified (IAPMO) to reduce lead, PFOA, PFOS, fluoride, arsenic, chromium-6, nitrate, chlorine taste and odor, chloramine, VOCs. It is also marketed for microplastics, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.287 per gallon.

   • Certified to reduce: lead, PFOA, PFOS, fluoride, arsenic, chromium-6, nitrate, chlorine taste and odor, chloramine, VOCs
   • Cartridge life: 600 gallons
   • Cost per gallon: $0.287
2. 26.1

   iSpring RCC7 5-Stage RO

   The iSpring RCC7 5-Stage RO is a ro water filter. It is third-party certified (NSF) to reduce total dissolved solids (TDS). It is also marketed for lead, fluoride, arsenic, cadmium, chromium, copper, selenium, chlorine taste and odor, PFAS, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.024 per gallon.

   • Certified to reduce: total dissolved solids (TDS)
   • Cartridge life: 547,500 gallons
   • Cost per gallon: $0.024
3. 36.0

   Express Water RO5DX 5-Stage RO

   The Express Water RO5DX 5-Stage RO is a ro water filter. It is third-party certified (NSF) to reduce total dissolved solids (TDS). It is also marketed for lead, arsenic, fluoride, chromium, mercury, uranium, radium, chlorine taste and odor, chloramine, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.021 per gallon.

   • Certified to reduce: total dissolved solids (TDS)
   • Cartridge life: 4,380 gallons
   • Cost per gallon: $0.021
4. 44.9

   Waterdrop G3P800 Tankless RO

   The Waterdrop G3P800 Tankless RO is a ro water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, total dissolved solids (TDS), lead, fluoride, cadmium, chromium-6, selenium. It is also marketed for PFOA, PFOS, arsenic, nitrate, mercury, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.123 per gallon.

   • Certified to reduce: chlorine taste and odor, total dissolved solids (TDS), lead, fluoride, cadmium, chromium-6, selenium
   • Cartridge life: 2,200 gallons
   • Cost per gallon: $0.123
5. 54.3

   Home Master TMAFC-ERP Artesian RO

   The Home Master TMAFC-ERP Artesian RO is a ro water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for chlorine taste and odor, chloramine, lead, fluoride, total dissolved solids (TDS), arsenic, pharmaceuticals, microplastics, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.038 per gallon.

   • Certified to reduce: nothing certified (claims are 'tested to' only)
   • Cartridge life: 27,375 gallons
   • Cost per gallon: $0.038
6. 64.0

   APEC ROES-50 Essence RO

   The APEC ROES-50 Essence RO is a ro water filter. It is third-party certified (WQA) to reduce total dissolved solids (TDS). It is also marketed for chlorine taste and odor, lead, arsenic, fluoride, VOCs, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.145 per gallon.

   • Certified to reduce: total dissolved solids (TDS)
   • Cartridge life: 550 gallons
   • Cost per gallon: $0.145