Why Test My Water Hardness?
Before you decide on a water softener, you need one crucial number: your water's hardness level. The good news? You don't have to be a chemist—or even leave your house—to find it. Below are four easy, accurate ways to measure hardness, plus a color-coded chart to understand what the results mean.
Key Takeaways
7 GPG = Decision Point
7+ GPG indicates hard water, calling for a water coniditioner or softener. Learn how to test water hardness quickly at home.
Test Strips: 30 Seconds, $10
The easiest home water hardness testing method is test strips for water hardness—just dip and read.
Free Reports for City Water
Call your utility for exact hardness numbers, check your city water hardness report online or request it free.
Traditional Water Softener vs. Salt-Free Softener
Water softeners use salt & regeneration. Salt-free systems need neither—choose based on water hardness results.
Why Does Hard Water Even Matter?
Read our full water hardness breakdown: Understanding hardness, what it is, why it matters, and so much more.
The Importance of Testing For Hard Water
Knowing your exact hardness—rather than just guessing from scale buildup—helps you size the correct water softener or decide if a salt-free conditioner is the right water treatment system. Undersize the unit and you'll refill salt every week; oversize and you'll unnecessarily overspend up-front.
How to Check For Hard Water
We now know why testing for water hardness is an important step to make an informed decision when it comes to picking a whole house water filtration system system. However, how do we actually conduct testing or measure how hard our water is? Let's go ahead and look over four different methods we can use to find our water hardness levels, ranging from quick and cheap, to comprehensive and in depth methods.
10 common signs of hard water you've overlooked →
4 DIY Ways to Test Water Hardness at Home
Outlined below are four various methods to test hard water, how much they cost, general accuracy, and how you can conduct the various tests.
Water Hardness Testing Methods
Here are four ways—ranging from quick DIY strips to lab-grade analysis—to determine your home's water hardness:
1. Home Water-Hardness Test Kits
Accuracy: ★★★★☆
Cost: $10-30
Water hardness test kits are available at hardware stores or online. They provide a quick color comparison to determine hardness levels, usually in GPG or PPM. Most provide enough materials for multiple tests so you can verify results.
- Test kit accuracy: ±1 GPG
- Color-coded hardness chart included
- Results in 30 seconds
2. Contact Your Local Water Utility
Accuracy: ★★★★★
Cost: Free
If you're on city water, call or email your local utility. They often test hardness weekly and will share the most recent number. Your city water hardness report is usually posted online in the annual Consumer Confidence Report, click to view.
- Contact local water utility directly
- Lab-grade testing results
- Historical hardness data available
3. Soap Bottle Test
Accuracy: ★★☆☆☆
Cost: Free
Fill a clear bottle with 10 oz of tap water, add 10 drops of pure liquid soap, and shake hard. If thick suds form and water stays clear, hardness is low. Little foam and cloudy water mean it's harder. Not precise, but good for a quick yes/no check.
- Soap versus scale test
- No equipment needed
- Qualitative results only
4. Professional Water Testing
Accuracy: ★★★★★
Cost: $100-300 or Free with consultation
Send a sample to a certified lab or schedule an in-home consultation. You'll get a full mineral panel, pH, iron, and manganese—all useful when choosing pre-filters or a water softener, reverse osmosis system or salt-free conditioner.
- Complete water quality analysis
- Professional recommendations included
- Identifies other contaminants
Read our hard water guide for more information about testing and interpreting your results →
Understanding Your Water Hardness Test Results
Once you've tested your water, understanding the results is crucial for determining if you need a water softener and what size system would be appropriate:
Water Hardness Scale
Need Help Understanding Your Water Hardness?
Crystal Quest offers expert analysis of your water hardness test results, with guidance to help you find the right water treatment solution.
Next Steps: Picking the Right Water Treatment System
Now that you know how to measure and understand water hardness at home, use your test results to select the ideal treatment solution. Whether using water hardness test kits or professional testing, your GPG number determines the best approach.
Choose Your Water Treatment System
Selecting the right treatment system is crucial for protecting your home's plumbing, appliances, and your family's comfort. Hard water doesn't just leave spots, it silently damages water heaters, clogs pipes, and increases energy bills. In fact, you might already be experiencing these 8 telltale signs that you need a water softener without realizing the root cause. The right system can save thousands in repairs while improving everything from your morning shower to your laundry's softness.
Water Softeners
Best for homes with 7+ GPG hardness
How Ion-Exchange Works
- Hard water enters resin tank
- Calcium and magnesium ions are captured
- Soft water exits to your home
- System regenerates automatically with salt
Stainless Steel Softener
48,000 Grain Capacity
- 9-11 GPM flow rate
- 1.5 ft³ resin tank
- Pre/post filtration included
- Digital metered control
Fiberglass Softener
60,000 Grain Capacity
- 10-13 GPM flow rate
- 2.0 ft³ resin tank
- Economical fiberglass construction
- Saves 75% salt, 64% water
Salt-Free Conditioners
Ideal for homes below 7 GPG - no salt or backwashing needed
How TAC Technology Works
- Water passes through specialized media
- Minerals transform into harmless crystals
- Crystals cannot stick to surfaces
- No regeneration or maintenance required
Salt-Free Water Conditioner
Stainless Steel System
- 9-11 GPM flow rate
- No salt or electricity needed
- Zero wastewater
- Keeps pipes spot-free
Salt-Free Water Conditioner
Fiberglass System
- 10-13 GPM flow rate
- Eco-friendly operation
- Retains healthy minerals
- Perfect for < 7 GPG
Reverse Osmosis Systems
For high TDS water - pairs perfectly with softeners
How Reverse Osmosis Works
- Pre-filters remove sediment and chlorine
- RO membrane filters microscopic impurities
- Post-filters enhance taste
- Purified water stored in tank
Under Sink RO System
17-Stage Filtration
- 50 gallons per day
- Removes 99% of contaminants
- Compact under-sink design
- Perfect for drinking water
Whole House RO System
Complete Home Solution
- 750 gallons per day
- Whole-house purification
- Ideal for high TDS water
- Bundles with softeners
Combination Systems
Complete solutions for a whole house water softener and filtration
Multi-Stage Treatment Process
- Whole house water filter first removes sediment, chlorine, PFAs, and much more.
- Next, the water softener treats hardness minerals
- *Carbon removes chemicals and odors
- Optional RO for ultimate purity
SMART Filter + Softener
Complete Whole House System
- Filtration + softening combo
- 9-13 GPM flow rate
- Perfect for water hardness and general filtration
- Optional UV sterilizer
SMART Filter + Water conditioner
Salt-Free SMART + Softener
- Filtration + conditioning
- Ideal for low maintenance hard water treatment GPG
- No salt required
- Optional leak detector SMART valve
Your Water, Your Choice—Test Today
Testing your water hardness isn't just about numbers—it's about making an informed decision that protects your home and improves your daily life. Whether you grab test strips for $10 or call your utility for free results, knowing your exact GPG puts you in control. At 7+ GPG, a water softener becomes your best investment. Below that? A salt-free conditioner might be perfect. Don't let hard water silently damage your plumbing while you wait—test today, and choose the Crystal Quest solution that matches your results.
Frequently Asked Questions
How to test water hardness at home for free?
The soap bottle test costs nothing—just use dish soap and a plastic bottle. For accurate free results, city water users should request their water utility's annual hardness report. Many utilities post these online or will email them upon request.
What is considered "hard" water?
Anything over 7 grains per gallon (≈120 mg L) is classified as hard.
How often should I test?
City-water users: once a year. Well owners: every 6 months or after heavy rains, plumbing work, or pump replacement.
Will boiling water remove hardness?
Boiling can precipitate temporary hardness but won't solve whole-house scale problems.
What's the difference between GPG and PPM/mg/L?
GPG (grains per gallon) is the traditional U.S. measurement for water hardness, while PPM (parts per million) or mg/L (milligrams per liter) are metric measurements. To convert: 1 GPG = 17.1 PPM. Most U.S. water softener companies use GPG, but your water utility report might show PPM. Our table above shows both for easy reference.
My test shows borderline results (6-8 GPG). What should I do?
At 6-8 GPG, you're in the "decision zone." Consider these factors: If you're already noticing scale buildup, dry skin, or dingy laundry, lean toward a water softener. If you prefer a maintenance-free solution and can tolerate minor spotting, a salt-free conditioner works well. Pro tip: Test multiple times—hardness can fluctuate seasonally. When in doubt, our water specialists can analyze your specific situation.
