Watsonville, CA tap water
Supplied by City of Watsonville. Here's what its 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)
11 ppm (Worth knowing)
Water changes can't take your tank's nitrate below this level.
From California Water Board lab results (2023–2026).
Copper at home taps
0.15 ppm (Worth knowing)
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).
Water chemistry
General hardness
185–340 ppm
Typical 220 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)
165–260 ppm
Typical 175 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
7.3–8.2
Typical 7.8
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results, measured before treatment (2023–2026).
Total dissolved solids
280–460 ppm
Typical 335 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).
Who supplies Watsonville, CA
City of Watsonville
Serves all residents · Lake or river water · 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.
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.