Best Water Hardness Test Kits (2025)

Accurate, affordable ways to measure your water hardness at home. We compare test strips, titration kits, and multi-parameter options.

6 min readUpdated January 2025

Our Top Picks

Hach

5-B Hardness Test Kit

$25-35

Homeowners wanting lab-accurate results without lab costs

Pros

  • +Professional-grade accuracy
  • +Easy drop-count method

Cons

  • -More expensive than strips

JNW Direct

Hard Water Test Strips (150 count)

$10-15

Quick checks and ongoing monitoring

Pros

  • +Very affordable per test
  • +Results in seconds

Cons

  • -Less precise than titration

API

GH & KH Test Kit

$10-15

Those who want general and carbonate hardness readings

Pros

  • +Tests both general and carbonate hardness
  • +Accurate drop-count method

Cons

  • -Designed for aquariums (works for tap too)

WaterSafe

City Water Test Kit

$15-20

First-time testers wanting comprehensive results

Pros

  • +Tests hardness plus 7 other parameters
  • +Good for overall water quality check

Cons

  • -Only 1 test per parameter

Quick Comparison

ProductTypePriceBest For
Hach 5-BTitration$25-35Professional accuracy
JNW StripsTest Strips$10-15Quick, affordable tests
API GH & KHTitration$10-15GH + KH testing
WaterSafe CityMulti-test$15-20Comprehensive check

Why Test Your Water Hardness?

While city water reports provide average hardness levels, your home's water can vary. Factors like your location within the service area, pipe age, and seasonal changes affect your actual hardness levels.

  • Softener sizing — Exact GPG readings required for proper equipment sizing
  • Well water — No municipal data available—testing is the only way to know
  • Softener verification — Confirm your system is actually removing hardness
  • Symptom confirmation — Verify hard water is causing your issues before investing in treatment

How to Test Your Water

Test Strip Method

Quick
  1. 1Run cold water for 30 seconds
  2. 2Dip strip in water for 1-2 seconds
  3. 3Hold horizontally for 15 seconds
  4. 4Compare color to chart on bottle

Quick but less precise. Good for yes/no answers.

Titration (Drop) Method

Accurate
  1. 1Fill test vial to mark with water
  2. 2Add drops of reagent one at a time
  3. 3Swirl after each drop
  4. 4Count drops until color changes

Each drop = 1 GPG (typically). Very accurate.

Frequently Asked Questions