Del Mar, CA tap water
Supplied by City of del Mar. Here's what its 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
Nitrate (NO₃)
Supplier's figureNot detected (Low)
Not detected in testing, so water changes lower your tank's nitrate well.
From the utility that supplies yours: City of San Diego, which supplies City of del Mar (2023–2026).
Copper at home taps
0.25 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 (2024–2025).
Water chemistry
General hardness
Supplier's figure54–285 ppm
Typical 237 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From the utility that supplies yours: City of San Diego, which supplies City of del Mar (2025).
Carbonate hardness (alkalinity)
Supplier's figure46–155 ppm
Typical 110 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From the utility that supplies yours: City of San Diego, which supplies City of del Mar (2025).
pH
Supplier's figure7.4–9
Typical 8.3
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From the utility that supplies yours: City of San Diego, which supplies City of del Mar (2025).
Total dissolved solids
Supplier's figure105–634 ppm
Typical 532 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: City of San Diego, which supplies City of del Mar (2025).
Who supplies Del Mar, CA
City of del Mar
Serves 99% of residents · Buys water from City of San Diego · 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.
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.