South San Jose Hills, CA tap water
Supplied mostly by Three Valleys MWD, plus 2 other utilities. Here's what the 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
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 33 ppm (Low)
Typical 1.8 ppm
Low, so water changes lower your tank's nitrate well.
From California Water Board lab results; Metropolitan Water Dist. of So. Cal. and Three Valleys MWD and California Domestic Water Company, which supplies Rowland Water District (2023–2026).
Copper at home taps
Up to 0.12 ppm (Low)
Typically not detected
Not detected in testing. Water that sits in household pipes overnight can still pick some up.
From California Water Board lab results (2023–2026).
Water chemistry
General hardness
82–291 ppm
Typical 227 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From California Water Board lab results; Metropolitan Water Dist. of So. Cal. and Three Valleys MWD and California Domestic Water Company, which supplies Rowland Water District; Pomona - City, Water Dept. and La Puente Valley CWD and Covina Valley Water Company - Wholesale and Metropolitan Water Dist. of So. Cal. and Valley County Water Dist. and Walnut Valley Water District, which supplies Suburban Water Systems-San Jose (2023–2026).
Carbonate hardness (alkalinity)
68–220 ppm
Typical 106 ppm
Moderate buffering. pH should stay fairly steady.
From California Water Board lab results; Metropolitan Water Dist. of So. Cal. and Three Valleys MWD and California Domestic Water Company, which supplies Rowland Water District; Pomona - City, Water Dept. and La Puente Valley CWD and Covina Valley Water Company - Wholesale and Metropolitan Water Dist. of So. Cal. and Valley County Water Dist. and Walnut Valley Water District, which supplies Suburban Water Systems-San Jose (2023–2026).
pH
7–8.7
Typical 8.2
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From California Water Board lab results; Metropolitan Water Dist. of So. Cal. and Three Valleys MWD and California Domestic Water Company, which supplies Rowland Water District; Pomona - City, Water Dept. and La Puente Valley CWD and Covina Valley Water Company - Wholesale and Metropolitan Water Dist. of So. Cal. and Valley County Water Dist. and Walnut Valley Water District, which supplies Suburban Water Systems-San Jose (2023–2026).
Total dissolved solids
160–666 ppm
Typical 310 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; Metropolitan Water Dist. of So. Cal. and Three Valleys MWD and California Domestic Water Company, which supplies Rowland Water District; Pomona - City, Water Dept. and La Puente Valley CWD and Covina Valley Water Company - Wholesale and Metropolitan Water Dist. of So. Cal. and Valley County Water Dist. and Walnut Valley Water District, which supplies Suburban Water Systems-San Jose (2023–2026).
- Suburban Water Systems-San Jose adds phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies South San Jose Hills, CA
Three Valleys MWD
Serves 58% of residents · Lake or river water · Chloramine
Rowland Water District
Serves 32% of residents · Buys water from Metropolitan Water Dist. of So. Cal. · Chloramine
Suburban Water Systems-San Jose
Serves 28% of residents · Buys water from Pomona - City, Water Dept. · 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.