Prunedale, CA tap water
Supplied mostly by Cwsc Oak Hills, plus 1 other utility. Here's what the water means for your fish.
Disinfectant
Chlorine
Your water is treated with chlorine. It slowly gases off from standing water, and any water conditioner removes it.
Safety for fish and shrimp
Nitrate (NO₃)
2.7–30 ppm (Low)
Typical 4.4 ppm
Low, so water changes lower your tank's nitrate well.
From California Water Board lab results, measured before treatment (2023–2026).
Copper at home taps
0.16–0.5 ppm (Worth knowing)
Typical 0.16 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 (2023–2026).
Water chemistry
General hardness
74–300 ppm
Typical 240 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From California Water Board lab results, measured before treatment (2023–2026).
Carbonate hardness (alkalinity)
79–170 ppm
Typical 140 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment (2023–2026).
pH
7–7.6
Typical 7.3
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results; California Water Board lab results, measured before treatment (2023–2026).
Total dissolved solids
245–640 ppm
Typical 500 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 (2023–2026).
- Psmcsd - Normco adds phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Prunedale, CA
Cwsc Oak Hills
Serves 26% of residents · Groundwater (wells) · Chlorine
Psmcsd - Normco
Serves 7% of residents · Groundwater (wells) · Chlorine
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.