We test each under-sink filter for contaminant reduction, installation ease, and long-term cost. No manufacturer has editorial influence.
Frequently Asked Questions
What's the best under-sink filter for lead?
The Aquasana AQ-5200 and AQ-5300+ are NSF-certified for lead reduction. The Waterdrop G3P800, iSpring RCC7AK, and APEC ROES-50 (all RO systems) remove 99%+ of lead. For municipal water with lead concerns—from plumbing or service lines—either a certified carbon filter or RO will work. RO provides the most thorough removal. If you're on a budget, the Aquasana AQ-5200 offers certified lead reduction without the cost of RO.
Do under-sink filters remove PFAS?
Yes, but not all. The Aquasana AQ-5200 is NSF-certified for PFOA and PFOS reduction. RO systems like the Waterdrop G3P800 and iSpring RCC7AK also remove PFAS effectively. Standard carbon filters vary—look for NSF P473 or PFOA/PFOS certification. If you're in an area with known PFAS contamination, choose an NSF-certified model or RO system for best removal.
Do I need electricity for an under-sink filter?
Carbon filters typically don't need electricity—they work by water pressure alone. RO systems vary: traditional tank RO (iSpring, APEC) don't need power; tankless RO with UV (Waterdrop G3P800) and some pumps (Home Master TMA) require an outlet. If you don't have an outlet under your sink, stick with carbon filters or traditional tank RO.
What's the waste water ratio for RO systems?
Traditional RO systems waste 3-4 gallons for every 1 gallon of filtered water (3:1 or 4:1 ratio). The Waterdrop G3P800 achieves 3:1. The Home Master TMA with permeate pump reduces this to 1:1 or better. If you're concerned about water waste, consider a non-RO carbon filter or a high-efficiency RO like the Home Master. In areas with water scarcity, the waste ratio matters.
