What water treatment system do you actually need?
Enter your water test results — hardness, iron, pH, flow rate — and get a sized system recommendation with the arithmetic shown, every number traced to a public source you can check.
Why this exists
The facts are public. Nobody assembled them.
EPA publishes contaminant limits. USGS publishes hardness data. NSF publishes what each certification actually covers. University extension programmes publish treatment guidance. It is all free, all scattered, and almost never assembled into an answer — so most people researching an $1,800 purchase end up reading marketing copy from the company selling the thing.
Every number is cited
No claim reaches a page without a source, a verbatim quote from it, and the date it was captured. The build refuses to compile a page that cites anything unverified.
The arithmetic is shown
Sizing is worked through on the page rather than hidden inside a calculator. If you disagree with a step, you can see which step.
Limits stated first
Every page says who it is not for and what the recommendation will not fix. A softener does not remove iron. Salt-free conditioners do not reduce hardness.
Start here
Well water, in depth
Private wells fall outside the enforceable standards that cover public water systems. Nobody tests yours for you.
Iron in well water — which filter actually removes it
Which iron filter do I need, given my iron level and the form it is in?
Water hardness and softener sizing — the arithmetic, shown
Do I need a softener, and what capacity should I buy?
Well water testing — what to test for, and how to read the report
What should I test my well for, and what do the numbers on the report mean?