Which water filter do I need?
It depends on what your test found. Here is what EPA names for each problem.
Reverse osmosis
- Nitrate
- Nitrite
- Arsenic
- Lead
- Copper
- Fluoride
- Uranium
- Total Dissolved Solids (TDS)
- Sulfate
- Chloride
- Sodium
- PFAS (PFOA and PFOS)
Also: distillation, everything here except PFAS (PFOA and PFOS).
Disinfection (chlorination)
Aeration
Point-of-use filter certified to remove lead
Water softener (ion exchange)
Acid neutralization / corrosion control treatment
Granular activated carbon (GAC), anion exchange, or nanofiltration
No test yet? Find a low-cost test near you.
From EPA and USGS pages checked October 1, 2026.