Learn

The knowledge layer: read these and no filter salesperson - or website - can blur the paperwork on you again.

42 vs 53 vs 58 vs 401 vs 372 - and certified vs tested vs marketing.

The EPA rules (including the 2025 change), and which filters are actually certified.

No safe level - and the practical fixes, from flushing to certified filters.

Free reports, lab panels and the well-owner's annual list.

What each technology actually removes, wastes and costs.

Point-of-use or point-of-entry - the decision guide.

And the salt-free truth nobody puts in the headline.

Testing and treatment order for the 43 million Americans on private wells.

Moon water, glow water, crystal bottles, cancer-cure claims - the strange corners, graded on evidence.