Free tool
What's in your tap water?
Search your city to see its tap water range for GH, KH, pH, nitrate and more, whether it's treated with chlorine or chloramine, and what that means for your fish.
Largest cities
Tap water lookup covers US cities only for now.
Our data comes from public records and is still incomplete. Many utilities don't publish every number, so we're adding more all the time. Your city's range is a starting point: testing your own tap is the only way to know exactly what's in it.
The Current · Investigation
Your tank starts at the tap
About 4 in 10 Americans on public water get chloramine, and hardness varies more than thirtyfold between cities.
Read the story