Citizen science, in plain language
How to read your strip.
You got a kit. You dipped the strip. Now there are colors. Here's what they're trying to tell you — and, just as important, what they're not.
The basics
- 01Run cold tap water for 30 seconds. You want the water that's actually in your pipes, not what's been sitting there.
- 02Dip the strip for the time on the packet. Usually a second or two. Don't leave it in. Don't wave it around.
- 03Wait the stated time. The pads keep changing color for a bit. Read at the time the packet says — not earlier, not ten minutes later.
- 04Compare in daylight if you can. Hold the strip next to the color chart. Kitchen lighting lies.
- 05Write it down and take a photo. Photo + approximate location + tag @h2ofaucet gets you the drip.
What each pad means
pH
How acidic or basic your water is. Most tap water lands near the middle of the scale.
Keep in mind: A slightly high or low reading is common and usually reflects your local source or pipes.
Hardness
How much dissolved mineral (mostly calcium and magnesium) is in the water.
Keep in mind: Hard water is a taste and soap-lather thing, not a safety verdict. Iowa water is often hard.
Chlorine
The disinfectant most cities add on purpose to keep water safe in the pipes.
Keep in mind: Some chlorine is expected. It's the reason tap water travels safely.
Iron
Dissolved iron, often from older pipes or well sources.
Keep in mind: Can affect taste and leave stains. A strip reading is a hint, not a measurement.
Nitrate / Nitrite
Compounds that can come from fertilizer runoff, especially in farm country.
Keep in mind: If a strip suggests an elevated reading, the right next step is a certified lab test — not a guess.
Alkalinity
The water's ability to resist pH changes.
Keep in mind: Mostly a chemistry curiosity for your own notes.
Exact pads vary by kit. The chart on your packet is the source of truth for your strip.
What a strip can't tell you
This part matters more than the colors.
- A strip gives a rough range, not an exact number.
- Lighting, timing, and eyesight all change the read. Two people can honestly disagree.
- Strips can't detect most things that matter for health — bacteria, lead below a threshold, PFAS, pesticides. Absence of a color change is not proof of safety.
- A strip is a snapshot of one glass, one moment. It says nothing about yesterday or tomorrow.
- If anything on the strip worries you, contact your local water utility or a state-certified lab. In Iowa, the State Hygienic Laboratory offers testing. That's the authoritative path.
The fine print, in normal words
These kits are for curiosity and citizen science. They are educational test strips — not lab instruments, not medical advice, not a safety certification. If you have a real concern about your water, use a certified lab. If your water tastes fine and the strip looks boring, that's a perfectly good result. Boring is underrated.
The faucet doesn't diagnose. The faucet just drips.
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