Poway, CA tap water
Supplied by City of Poway. Here's what its water means for your fish.
Disinfectant
Chloramine
Your water is treated with chloramine. Unlike chlorine, it doesn't gas off when water sits out, and many pitcher and fridge filters aren't rated to remove it. Conditioners that list chloramine on the label break it apart, which frees a little ammonia. Some utilities switch to plain chlorine for a few weeks a year.
Safety for fish and shrimp
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From California Water Board lab results (2024–2025).
Nitrate (NO₃)
0.8–2.1 ppm (Low)
Typical 1.6 ppm
Low, so water changes lower your tank's nitrate well.
From California Water Board lab results (2024–2025).
Copper at home taps
0.03 ppm (Low)
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results (2025).
Water chemistry
General hardness
236 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From California Water Board lab results, measured before treatment (2023–2025).
Carbonate hardness (alkalinity)
111 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment (2023–2025).
pH
8.1
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From California Water Board lab results, measured before treatment (2023–2025).
Total dissolved solids
536 ppm
A rough measure of everything dissolved in the water. RO water reads near 0, so TDS is a quick way to compare waters.
From California Water Board lab results, measured before treatment (2023–2025).
Who supplies Poway, CA
City of Poway
Serves all residents · Lake or river water · Chloramine
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.
Tap water lookup covers US cities only for now. Want to know why it matters? Read our story on tap water.
Compiled by Shoal & Stem from public records. Free to cite with a link.