Knightsen, CA tap water
About 28% of Knightsen is inside a utility's service area. Homes outside it likely use private wells, which no utility tests.
Disinfectant
Chlorine or chloramine
Utilities here use chlorine or chloramine, depending on which one serves your address. Chlorine slowly gases off from standing water; chloramine doesn't. Private wells aren't treated by a utility, so there's no chlorine or chloramine unless a treatment system adds it.
Safety for fish and shrimp
Ammonia
0.4–0.64 ppm (Worth knowing)
Typical 0.52 ppm
Ammonia in the water as delivered. A cycled filter clears it within a day; a big water change in a new or very small tank adds more of it at once.
From California Water Board lab results (2023–2025).
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 (2023–2026).
Nitrate (NO₃)
Up to 2.4 ppm (Low)
Typical 1.3 ppm
Low, so water changes lower your tank's nitrate well.
From California Water Board lab results, measured before treatment; California Water Board lab results (2023–2026).
Copper at home taps
Up to 0.01 ppm (Low)
Typical 0.01 ppm
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results (2023–2025).
Water chemistry
General hardness
124–270 ppm
Typical 270 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From California Water Board lab results, measured before treatment; California Water Board lab results (2023–2024).
Carbonate hardness (alkalinity)
70–241 ppm
Typical 241 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment; California Water Board lab results (2023–2024).
pH
7.7–8.3
Typical 7.7
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results, measured before treatment; California Water Board lab results (2023–2024).
Total dissolved solids
150–533 ppm
Typical 533 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; California Water Board lab results (2023–2025).
Who supplies Knightsen, CA
Knightsen Community Water System
Serves 22% of residents · Groundwater (wells) · Chlorine
Diablo Water District
Serves 5% of residents · Buys water from Randall-Bold Water Treatment Plant · 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.