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Own a water softener without guessing

Measure first, size second, adjust third. Every figure on this site comes with its unit, its source and its limits.

Start with the complete water softener guide

Four steps, in this order

  1. Measure

    Water Hardness Guide: GPG, PPM and What to Measure

    Understand water hardness levels in gpg, ppm and mg/L. Convert your result, read USGS ranges and choose the right next step before adjusting a softener.

  2. Size

    Water Softener Sizing Calculator

    Estimate usable water softener capacity from measured hardness, daily softened-water use, target days and a visible planning reserve without hidden defaults.

  3. Set

    How to Set Water Softener Hardness

    Set hardness from untreated water, convert mg/L to gpg, follow exact-model rules for rounding, iron or potassium, and verify the result after a completed cycle.

  4. Verify

    Printable Water Softener Maintenance Log

    Download a printable water softener maintenance log to track model details, hardness tests, salt, regenerations, inspections, service and next due dates.

Six-stage water softener decision map covering measurement, treatment fit, sizing and verification, model-specific configuration, maintenance records, and safe troubleshooting.

Six-stage water softener decision map covering measurement, treatment fit, sizing and verification, model-specific configuration, maintenance records, and safe troubleshooting.

Read diagram in text
  • OWNER PLAN
  • One verified hardness result carried through six stages
  • 1
  • Measure
  • Hardness · Testing
  • Source and untreated
  • sample
  • Value with its unit
  • Conversion, unrounded
  • 2
  • Decide
  • Basics · Conditioners · City
  • Hardness fit
  • Broader contaminant
  • questions
  • Local and septic
  • constraints
  • 3
  • Size and verify
  • Units · Capacity · Sizing
  • Water use and daily load
  • Capacity at a stated
  • dose
  • Service flow
  • Exact certification
  • listing
  • 4
  • Configure
  • Settings · Set hardness
  • Exact model and manual
  • Old value and new value
  • Validation result
  • 5
  • Maintain
  • Regeneration · Maintenance
  • Inspect, test, clean
  • Professional service
  • Dated log entry
  • 6
  • Troubleshoot
  • Symptoms and fixes
  • Observable symptom
  • Safe evidence only
  • Stop before repair
  • The same hardness result, with its unit, carries through every stage
  • The article repeats this plan as an HTML table; the numbered path, not colour, carries the order.
  • Each label names the guides for that stage. A stage stays open until its evidence exists.

Open full diagram

An evidence-first water softener plan carries one verified hardness result through sizing, model verification, configuration, maintenance, and symptom-based troubleshooting.

Calculators

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Four water-hardness bands: soft through 60 milligrams per liter, moderately hard above 60 through 120, hard above 120 through 180, and very hard above 180, with approximate grains-per-gallon equivalents.

Four water-hardness bands: soft through 60 milligrams per liter, moderately hard above 60 through 120, hard above 120 through 180, and very hard above 180, with approximate grains-per-gallon equivalents.

Read diagram in text
  • USGS water-hardness classes
  • mg/L as CaCO3, with calculated grains-per-gallon equivalents
  • Soft
  • 0 – 60 mg/L
  • 0 – 3.50 gpg
  • Moderately hard
  • 61 – 120 mg/L
  • 3.51 – 7.01 gpg
  • Hard
  • 121 – 180 mg/L
  • 7.02 – 10.51 gpg
  • Very hard
  • over 180 mg/L
  • over 10.51 gpg
  • 60 mg/L
  • 3.50 gpg
  • 120 mg/L
  • 7.01 gpg
  • 180 mg/L
  • 10.51 gpg
  • open
  • Classify with the unrounded mg/L value. GPG boundaries are calculated equivalents.
  • 1 gpg = 17.12 mg/L as CaCO3, applied in both directions. Bands are a hardness scale only — they are not a drinking-water safety rating.

Open full diagram

USGS water-hardness classes in mg/L as CaCO3, with gpg equivalents calculated using 1 gpg = 17.12 mg/L.

Printable sheets

Print at 100% on US Letter. No email, no sign-up.

Budget and quote worksheets

Compare the same scope before comparing totals. Each sheet includes a blank CSV and a clearly labeled illustrative example.

Compare capacity and salt dose for six documented models, or check dated equipment prices and their exclusions.

Step-by-step, with the safety limits

Where to look

How this site works

We begin with primary sources whenever possible, including government guidance, official standards information, certification databases, performance data sheets, and exact manufacturer manuals. Calculations include visible formulas and test cases. Model-specific instructions stay attached to the cited model.

Unless a page explicitly documents otherwise, product details come from manufacturer documents and official certification listings, not from our own testing, and we do not rank or endorse brands. The site does not determine whether water is potable, replace an exact manual or local requirements, or provide electrical, plumbing, medical, legal, or professional water-treatment services.

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