La Crescenta-Montrose, CA tap water
Supplied mostly by Crescenta Valley CWD, plus 1 other utility. 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 (2026).
Nitrate (NO₃)
Up to 33 ppm (Worth knowing)
Typical 21 ppm
High for tap water. Water changes can't take your tank's nitrate below this level.
From California Water Board lab results; Metropolitan Water Dist. of So. Cal., which supplies Foothill Municipal Water Dist. (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 (2023–2026).
Water chemistry
General hardness
82–360 ppm
Typical 340 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal., which supplies Foothill Municipal Water Dist. (2023–2026).
Carbonate hardness (alkalinity)
68–170 ppm
Typical 150 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal., which supplies Foothill Municipal Water Dist. (2023–2026).
pH
6.7–8.7
Typical 6.9
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal., which supplies Foothill Municipal Water Dist. (2023–2026).
Total dissolved solids
214–666 ppm
Typical 560 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; Metropolitan Water Dist. of So. Cal., which supplies Foothill Municipal Water Dist. (2023–2026).
Who supplies La Crescenta-Montrose, CA
Crescenta Valley CWD
Serves 50% of residents · Buys water from Foothill Municipal Water Dist. · Chloramine
Foothill Municipal Water Dist.
Serves 50% of residents · Buys water from Metropolitan Water Dist. of So. Cal. · 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.