Water testing in Phoenix, AZ

Why test water in Phoenix at all?

The City of Phoenix’s yearly water quality report for 2025 gives one hardness range for the whole system: 10 to 17.6 grains per gallon (172 to 302 parts per million). The city doesn’t break it down by ZIP code or neighborhood. Phoenix mixes river, canal and well water, so the number at your tap can sit anywhere in that range. Water testing in Phoenix AZ is the only way to know where your home falls. Our page on Phoenix water hardness explains the range and why it moves.

For a softener, that matters: the hardness you enter decides how often it recharges and how much salt it uses. For drinking water safety, the city’s own testing already covers the public supply; private wells are different (see below).

How can you tell if you have hard water?

You can usually see it before you test it. The City of Phoenix says hard water can cause scaling in pipes and water heaters and on faucets and showerheads. The University of Nebraska–Lincoln Extension adds poor soap and detergent performance: soap lathers less and leaves a film. White spots on glasses and shower glass are the same minerals; our guide to removing hard water stains covers cleanup. Signs tell you hardness is there. A test tells you how much.

Hard water test strips and kits

A hard water test kit is the quickest way to get your own number. Strips are the simplest kind.

How to use a hardness test strip

Hach, which makes laboratory and field test supplies, publishes the details for its total hardness strips:

• Range: 0 to 425 parts per million, or 0 to 25 grains per gallon.
• Color steps: 0, 25, 50, 120, 250 and 425 ppm, which Hach lists as 0, 1.5, 3, 7, 15 and 25 grains per gallon.

Dip the strip in cold tap water, wait the time on the package, and match the pad to the color chart. If the color falls between two blocks, your water is between those two numbers. Phoenix’s published range sits between the 7 and 25 blocks, so expect a reading near 15 and treat it as an estimate.

Use a tap that isn’t softened or filtered: an outdoor hose bib or the cold line before any softener. The same strips work anywhere in Arizona; in Tucson, where the utility publishes no single figure, they are the main way to find your Tucson water hardness. If you already have a softener, test both before and after it. A softener manual from Pentair says to test softened water with strips at least twice a year to make sure the system is working.

How accurate are hard water test strips?

They give a good estimate, not a precise figure. The University of Nebraska–Lincoln Extension says home hardness kits and dip strips “are generally easy to use, relatively inexpensive, and can provide a good estimate of hardness,” and that a lab test is worth considering when you need a more accurate measurement. Hach doesn’t publish a plus-or-minus accuracy figure for its strips, only the steps above. For setting a softener, the nearest step is close enough; round up.

Once you have a number, our page on the softener hardness setting shows how to enter it on the control valve.

Water quality testing in Arizona: licensed labs

A strip tests hardness only. For arsenic, nitrates, bacteria, lead or anything else, use a laboratory licensed by the Arizona Department of Health Services (ADHS). ADHS keeps a public list of licensed commercial drinking water labs at azhealth.gov/labs4h2o, with each lab’s address and phone number, updated daily. ADHS notes that not every lab runs every test, so call first and say what you want tested. Its laboratory office answers questions at (602) 364-0720. ADHS’s own guides note that private labs test for a fee.

If your home is on a private well

City customers get their water tested by the utility. Well owners are responsible for their own. ADHS’s checklist for private well owners (July 2025) recommends testing:

• Every year: bacteria (total coliform) and nitrates.
• Every 5 years: arsenic, fluoride and uranium.

If arsenic is the concern, ADHS’s arsenic guide for well owners says home filters like reverse osmosis remove it, and that boiling water does not remove arsenic and may increase the concentration.

Free water testing in Phoenix: what to expect

Free in-home water tests are often offered by companies that sell water treatment equipment. That doesn’t make the result wrong, but the test is part of a sales visit, and it may be followed by a recommendation to buy that company’s system. Treat it as a first look, not a final answer.

Before you sign anything:

• Check the hardness yourself with a strip, or compare it with the city’s published range.
• For anything beyond hardness, get a result from an ADHS-licensed lab.
• Ask what was tested, with what method, and for the result in writing, in grains per gallon or parts per million.

We don’t sell or install water treatment, so we have no stake in which you choose. Our page on how we get our data explains where every figure on this site comes from.

Where these facts come from

• City of Phoenix Water Services Department · yearly water quality report and water services web pages · 2025 data · hardness range, no hardness by ZIP code, scaling effects, compliance statement.
• Hach · product page for its total hardness test strips · undated · range and color steps.
• University of Nebraska–Lincoln Extension · drinking water fact sheet on hard water · 2016 · strips give a good estimate; lab for accuracy; soap effects.
• Pentair · installation and owner’s manual for a whole-house softener · undated · test softened water at least twice a year.
• Arizona Department of Health Services · licensed drinking water lab lookup, private well owner checklist (2025) and arsenic guide for well owners (2024) · lab list and phone, well testing schedule, arsenic and reverse osmosis.
• Tucson Water · hard water web page · current page · pool test kit tip for home hardness.