Monterey, CA tap water
Supplied by Cal Am Water Company - Monterey. 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
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 (2023–2025).
Nitrate (NO₃)
0.6–21 ppm (Worth knowing)
Typical 11 ppm
Water changes can't take your tank's nitrate below this level.
From California Water Board lab results (2023–2026).
Copper at home taps
0.38 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 (2023–2025).
Water chemistry
General hardness
130–209 ppm
Typical 161 ppm
Moderately hard. Great for livebearers, and most community fish adapt.
From California Water Board lab results, measured before treatment (2023–2025).
Carbonate hardness (alkalinity)
130–145 ppm
Typical 144 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results (2023–2026).
pH
7.2–7.4
Typical 7.4
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results (2023–2026).
Total dissolved solids
106 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 (2023–2026).
- Cal Am Water Company - Monterey adds phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Monterey, CA
Cal Am Water Company - Monterey
Serves all residents · Groundwater fed by surface 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.