Milpitas, CA tap water
Supplied mostly by City of Milpitas, plus 1 other utility. Here's what the 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 (2025–2026).
Nitrate (NO₃)
Supplier's figureUp to 1.9 ppm (Low)
Typically not detected
Not detected in testing, so water changes lower your tank's nitrate well.
From the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System and Sfpuc City Distribution Division, which supplies City of Milpitas; California Water Board lab results (2013–2026).
Copper at home taps
Up to 0.03 ppm (Low)
Typical 0.03 ppm
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results (2025–2026).
Water chemistry
General hardness
Supplier's figure8–106 ppm
Typical 70 ppm
Soft. Good for tetras, rasboras and most shrimp. Livebearers, snails and African cichlids prefer harder water.
From the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System and Sfpuc City Distribution Division, which supplies City of Milpitas; California Water Board lab results (2023–2026).
Carbonate hardness (alkalinity)
Supplier's figure8–102 ppm
Typical 68 ppm
Moderate buffering. pH should stay fairly steady.
From the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System and Sfpuc City Distribution Division, which supplies City of Milpitas; California Water Board lab results (2023–2026).
pH
Supplier's figure7.6–9.2
Typical 8.3
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System and Sfpuc City Distribution Division, which supplies City of Milpitas; California Water Board lab results (2023–2026).
Total dissolved solids
Supplier's figure24–279 ppm
Typical 146 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 the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System and Sfpuc City Distribution Division, which supplies City of Milpitas; California Water Board lab results (2023–2026).
- City of Milpitas and Santa Clara Valley Water District add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Milpitas, CA
City of Milpitas
Serves all residents · Buys water from Santa Clara Valley Water District · Chloramine
Santa Clara Valley Water District
Serves 49% of 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.
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Compiled by Shoal & Stem from public records. Free to cite with a link.