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Water Filter Testing Comparison

Posted by richard on Jun 4th 2026

I've promised this (amongst other things) for over a year now.

Probably much of it is what you already expected.

The test compares:

  1. Well water from the wellhead (112 analytes)
  2. Kinetico filter/softener combo aka Kitchen sink (112 analytes, radon, PFAS [teflon])
  3. Reverse osmosis after above filter/softener combo (112 analytes)
  4. Distiller after above filter/softener combo (112 analytes, radon, PFAS [teflon])

See spreadsheet here.

Caveats and notes:

  1. A LLM helped compile and organize the data into the spreadsheet. Original test results are linked in the raw data sheets.
  2. The wellhead water test was taken about 1.5 to 3+ months before the other tests.
  3. All water after the wellhead is routed through PVC, a pressure tank, and PEX pipe.
  4. The distiller water passes through an in-line pump and a VOC filter before the faucet.
  5. The chlorine filter (part of the Kinetico filter/softener combo) probably isn't necessary as I'm on well water and seemed to add chlorine and it's byproducts (THM) to the system.
  6. The first sheet contains more caveats and notes.

Key Findings:

Let me know what you think.

!