The only way to really know what’s in your water is by having it tested. Because many water quality problems can’t be seen, tasted or smelled, regular testing is critical – especially if your home relies on a private well. Various testing approaches can measure different characteristics of your tap water, from hardness, pH level and iron to potentially serious contaminants such as lead, PFAS (forever chemicals) or bacteria.
While DIY test kit options are available, the most accurate way to understand your water quality is professional testing with a local water expert. This can include sending water samples to a certified laboratory, depending on your water source and your concerns.
In this guide, you’ll learn:
- When and why to test your water
- How each testing method works
- How to interpret your test results
- Steps to take if you identify issues
Why and when should you test your water?
In general, if you are interested in learning more about your water quality, you should have it tested. But there are also a number of situations where testing is specifically recommended for homeowners:
- Moving into a new home to establish a baseline of your home’s water quality
- Using a private well (test once a year), with additional tests after flooding events, well repairs or changes in taste, odor or appearance
- Newly pregnant or bringing an infant into the household, since certain contaminants like nitrates pose higher risks to vulnerable populations
- Upgrading plumbing or water system, as construction can dislodge sediment or increase exposure to metals like lead or copper
- Hearing local reports of potential water quality issues, like forever chemicals or lead
- Noticing signs of possible water problems, such as staining on fixtures, hard water scaling or unpleasant odors
- If you haven’t tested your water before, it’s always a good idea to have an idea of its quality to determine if you want to take steps to improve it.
Should you test your water even if it comes from a city/municipal source? Yes. Even though these supplies are protected through federal drinking water standards, these focus on contaminants that could affect your health, they don’t always address other water issues that can impact your home’s comfort and convenience—like hardness, taste or odor. So your tap water can still leave behind spots on dishes, buildup around sinks and faucets, or an unpleasant taste or smell.
In addition, newer concerns—including microplastics, pharmaceuticals, and PFAS (often called “forever chemicals”)—are still being studied and aren’t yet fully regulated. That means many public water systems aren’t equipped to filter them out. And even treated water can pick up lead, iron, or disinfection byproducts as it travels through aging pipes or household plumbing, potentially affecting both its safety and quality by the time it reaches your tap.
For well water users
Unlike municipal supplies regulated under the Safe Drinking Water Act in the U.S. and at the provincial or territorial level in Canada, private wells are not subject to quality monitoring. Homeowners are solely responsible for ensuring their wells deliver safe drinking water. Both the U.S. Centers for Disease Control (CDC) and Health Canada recommend testing at least once a year for bacteria, nitrates and region-specific chemical contaminants. In areas with intensive agriculture or industry, more frequent testing may be needed.
Testing your well water at regular intervals also helps track changes in your water supply over time. For example, shifts in local geology, weather patterns or land use can influence surface water and groundwater, potentially introducing new contaminants into your well.*
How to test water quality
Below are the three primary ways to test water quality. Each method provides different levels of insight, from a basic overview to detailed chemical testing for a more comprehensive view.
1. Professional in-home testing
Professional testing like Culligan’s in-home water testing provides fast and accurate results for common water quality issues. A local water expert can test your tap water for hardness, chlorine, pH levels, total dissolved solids and other concerns, with results in less than 30 minutes. These test results are explained on the spot, along with recommendations for water treatment solutions.
This type of in-home water quality testing is particularly valuable because it is personalized. With your test results, you’ll get system recommendations specific to your water issues as well as your plumbing, water usage and more. While some testing that can be completed in home covers aesthetic concerns like taste, odor and scaling, your local water expert can recommend additional lab testing when health-related contaminants or other contaminants are suspected.
“A detailed water test is the most important thing you can do for your home,” says Maria Mozden, Senior Lab Manager at Culligan. “While it is important for everyone, it is especially important if you’re on a private well, as the EPA recommends testing at least once a year — yet some well owners go 20 years without ever doing it.”
Schedule your free water test.
2. Certified lab testing
For the most comprehensive water quality test, a certified laboratory can provide detailed microbiological and chemical testing. Typically, untreated water from your home is collected in a sample bottle and can be analyzed for a wide range of potential contaminants, including bacteria, nitrates, arsenic, PFAS, lead, copper and volatile organic compounds. Culligan’s IL EPA-certified lab, for example, offers more than 45 different types of water tests and processes hundreds of tests every day. Depending on the package purchased, standard lab testing may take three business days, while specialized analyses will take longer.
3. DIY home test kits
DIY at-home water testing kits often use test strips or colorimetric tablets to measure water quality indicators such as chlorine, hardness and total dissolved solids (TDS). A test strip changes color when dipped into a sample of tap water, which you then compare against a chart to interpret the test result.
These kits are useful for quick checks-—for example, identifying hard water or elevated chlorine levels — but they are less reliable for detecting trace chemical contaminants such as lead, arsenic or PFAS. For homes where water safety is a concern, DIY test kits should be viewed as a starting point rather than a comprehensive solution.
In-home testing by a water treatment expert, complemented where necessary with certified laboratory testing, is the best option when you need certainty about harmful contaminants or compliance with EPA and Health Canada guidelines for safe drinking water.
What should you test for?
Determining what to test for depends on your water source, your household and your region. Different contaminants are more likely to appear in city water from a public water system than in groundwater from a private well.
For city water users
As discussed above, homeowners connected to a municipal water system benefit from federal regulation; however, water quality issues can still be present for a variety of reasons. Water testing can identify issues such as:
- Hardness: Excess calcium and magnesium that can cause damaging buildup around your home (and on your hair and skin)
- Chlorine: Used for disinfection but can affect taste, odor and hair/skin dryness
Total dissolved solids: Known as TDS, this is a measure of the concentration of dissolved minerals, salts and metals in your water— high levels can affect both taste and appliance performance - pH: Elevated levels can make water can taste bitter and leave scale on faucets and appliances
- Contaminants of concern: You can also request testing specific to your own concerns, whether that’s lead, forever chemicals or something else.
For well water users
Private wells are not federally regulated, so homeowners are solely responsible for monitoring water quality. Well testing should focus on:
- Bacteria (coliform, E. coli): Indicators of water contamination from sewage or animal waste
- Nitrates: Often linked to agricultural runoff and particularly dangerous for infants; this is more common in specific regions (and in agricultural areas)
- Hardness: Very common in groundwater and a frequent cause of damaging mineral buildup
- Iron and manganese: Not harmful to heath but can cause staining and a metallic taste
- Arsenic and PFAS: Harmful chemical contaminants detectable only through laboratory analysis
Why professional guidance matters
While test kits can provide a snapshot, interpreting test results requires context. The “best” water quality testing strategy depends on your local environmental quality, your plumbing system and whether your home uses groundwater or surface water. Additionally, almost all of the tests listed above (with the exception of hardness, TDS, pH and chlorine) are generally laboratory tests that require expert equipment and analysis.
A professional consultation ensures that you use the right test to screen for the right contaminants, that results are correctly understood and that solutions are matched to your home’s unique water quality issues.
Understanding your test results
Reading a water quality test is just as important as collecting the water sample. DIY kits can provide quick comparisons, but they often leave questions about what the numbers truly mean.
Professional in-home testing offers more clarity, with a local water expert explaining results in real time. Certified laboratory testing delivers the most detailed analysis, though those results also require interpretation with help from a local water treatment expert to determine whether they indicate a concern.
Most harmful contaminants, such as lead, nitrates and certain bacteria, have no taste, smell or visible signs. This is why appearance alone is not a reliable measure of drinking water quality. Many homeowners also choose to reduce potentially harmful contaminants even when levels fall below U.S. EPA or Health Canada guidelines, especially when using a public water system where trace amounts of regulated substances may still be present.
Examples of common thresholds include:
- Hardness: Above 60 mg/L indicates moderately hard water (an aesthetic concern, not regulated).
- Lead: At or above 0.015 mg/L requires corrective action under EPA guidance.
- Nitrates: At or above 10 mg/L is unsafe for infants, as established by the EPA.
When should you take action?
Even when water quality test results are below federal or provincial action levels, you may choose to address them for peace of mind. However, you should take immediate steps if:
- A contaminant exceeds established guidelines such as the Safe Drinking Water Act in the U.S.
- You notice sudden changes in taste, odor or appearance that could indicate new contamination.
- Your household includes vulnerable populations such as infants, children or pregnant individuals
Take our quiz to find the right solution for your home.
Next steps: Improving your home’s water
Once you understand your water quality test results, the next step is addressing the specific water quality issues identified. The appropriate solution depends on your water source, the type of contaminants present, and your household’s needs.
Culligan offers several options for improving water quality, including:
- Water softeners: Address hardness minerals such as calcium and magnesium to protect plumbing, appliances, and hair and skin.
- Whole-home filtration systems: Target specific water quality issues such as chlorine, iron, arsenic, PFAS or sediment; treats your water where it enters your home.
- Reverse osmosis filtration systems: Reverse osmosis offers comprehensive filtration for a wide range of contaminants (Culligan’s is certified to reduce more than 90) where it matters most: at your kitchen tap.
Scheduling an in-home water test and consultation is the most effective way to determine which water treatment system is right for your household.
Home Water Testing FAQs
How do you measure the quality of drinking water?
Drinking water quality is measured using test kits (such as test strips), digital meters or certified laboratory analysis. These methods evaluate physical properties (like hardness), chemical contaminants (such as chlorine or lead) and biological parameters (such as bacteria). (Not all methods can address all types of contaminants.)
Which tests best help determine water quality?
There is no single “best” test for every home. The most useful testing depends on your water source, concerns and household conditions. City water users often prioritize chlorine, hardness and lead, along with any specific contaminant concerns, while well water users should focus on hardness as well as bacteria, nitrates and region-specific chemical contaminants. Professional guidance ensures you select the right water quality test for your needs.
How do I know if my drinking water is safe?
The only way to know what’s in your tap water is to test it. Culligan offers in-home water testing for common concerns like hardness and chlorine, as well as certified lab testing for harmful contaminants such as arsenic, nitrates and lead.
Cleaner water starts with clarity
Whether you’re testing out of caution or because of noticeable water quality issues, the first step toward clean water is clarity about what’s in your supply. Regular testing helps identify quality issues early and provides peace of mind.
Schedule your free in-home water test and consultation today and get personalized recommendations for protecting your household’s water system.
*Contaminants may not be present in your water.
