Santa Clara, CA tap water
Supplied mostly by City of Santa Clara Water & Sewer Utilities, 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)
Typical 0.8 ppm
Low, 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, which supplies City of Santa Clara Water & Sewer Utilities; California Water Board lab results (2023–2026).
Copper at home taps
Up to 0.13 ppm (Worth knowing)
Typical 0.13 ppm
Shrimp and snails are sensitive to copper. Water that sits in household pipes picks up the most; it drops once the tap has run for a minute.
From California Water Board lab results (2025–2026).
Water chemistry
General hardness
Supplier's figure8–106 ppm
Typical 86 ppm
Moderately soft to medium. Suits most community fish and plants.
From the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System, which supplies City of Santa Clara Water & Sewer Utilities; California Water Board lab results (2023–2026).
Carbonate hardness (alkalinity)
Supplier's figure8–102 ppm
Typical 76 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, which supplies City of Santa Clara Water & Sewer Utilities; California Water Board lab results (2023–2026).
pH
Supplier's figure7.6–9
Typical 8
Most community fish do well here. Stable water matters more than the exact number.
From the utility that supplies yours: Santa Clara Valley Water District and San Francisco Regional Water System, which supplies City of Santa Clara Water & Sewer Utilities; California Water Board lab results (2023–2026).
Total dissolved solids
Supplier's figure24–279 ppm
Typical 212 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, which supplies City of Santa Clara Water & Sewer Utilities; California Water Board lab results (2023–2026).
- City of Santa Clara Water & Sewer Utilities and Santa Clara Valley Water District add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Santa Clara, CA
- 2025 water quality report
City of Santa Clara Water & Sewer Utilities
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.