Free · private · browser-based

Plan your whole-house water system before you buy.

Turn your household size, hardness, flow needs and water-test clues into a practical treatment plan. No account, no API, no uploaded lab report.

Build my planI have a water test
0 data uploads17.1 mg/L = 1 gpg hardnessEPA/NSF source-led guidance

A better order of operations

1
Know the sourceMunicipal water and private wells start with different evidence.
2
Size for flowWhole-house equipment must pass the flow your home actually needs.
3
Match the problemHardness, sediment, iron and health contaminants are not interchangeable.
4
Check certificationMatch certification claims to the contaminant you actually want reduced.
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Hardness translated

Enter ppm/mg/L or grains per gallon. We normalize the number and show the USGS hardness class.

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Flow target

Use a known measured peak flow or a conservative bathroom-based planning estimate.

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Treatment order

Get a prioritized sequence without pretending a generic calculator can certify water safety.

Build your water-system plan

Use numbers from your utility Consumer Confidence Report (CCR) or a certified lab when you have them. Unknown fields can be left blank.

Planning estimate — not a water-safety determination. Verify health-related concerns with a certified lab/utility and verify final equipment, plumbing, certification and code requirements before purchase or installation. Safety & legal limits.

1. Home + water source

Leave blank for a planning estimate.
Planning default from the Penn State softener-sizing example; use your measured softened-water use if known.
Use a measured household value if you know it. Exclude irrigation or other water that bypasses the softener.

2. Water-test numbers

Used only to grade sizing confidence — not water safety.

3. Sizing preferences

A planning window, not a universal manufacturer setting.
Extra design margin for variation in use.

4. What are you seeing?

Check your utility CCR. Carbon performance claims differ by contaminant and product.

This tool estimates sizing and treatment sequence. It does not determine whether water is safe to drink and does not replace a certified lab, utility report, plumber, water-treatment professional or applicable code.

Before you buy

Five checks that prevent expensive mistakes

Verify the exact model's service flow, pressure drop, usable capacity, certified claim and ownership cost — then confirm installation requirements.

Open buying checklist

Useful calculators

Eight focused tools for sizing, comparing equipment and estimating ownership cost.

Product fit checkerCompare a candidate system’s service flow and usable capacity against your house.Buyer toolHardness converterppm / mg/L ↔ gpg + USGS classSoftener size calculatorDaily grains + planning capacity bandFlow-rate plannerEstimate simultaneous GPM from fixturesRegeneration intervalUsable capacity ÷ daily grain loadSalt-use calculatorRegeneration settings → annual salt cost10-year ownership costEquipment + install + consumables + energySoftener efficiencyCompare usable grains per pound of salt and estimate annual salt demand.
Built to reduce guesswork

Most calculators stop at a number. This one checks the decision.

Use the planner to size the need, then use the Product Fit Checker to test a real product’s service flow and usable capacity before you buy. The site never treats a nominal label as proof of fit.

Evidence gradeShows when the result rests on lab/utility data versus estimates.
Hydraulic checkCompares product service flow with your household target.
Usable-capacity checkSeparates nominal grain labels from the capacity you can actually enter.
Safety gateHealth-contaminant selection stays outside the generic sizing engine.

Start with evidence, not a product page.

Municipal water: read your CCR. Private well: use a certified laboratory before treating a health concern.

Read a water test