Aliso Viejo, CA tap water
Supplied by Moulton Niguel Water District. 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)
4–6.2 ppm (Low)
Typical 5.8 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
0.03 ppm (Low)
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results (2024).
Water chemistry
General hardness
Supplier's figure82–291 ppm
Typical 234 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
From the utility that supplies yours: Metropolitan Water Dist. of So. Cal., which supplies Moulton Niguel Water District (2023–2026).
Carbonate hardness (alkalinity)
Supplier's figure68–126 ppm
Typical 106 ppm
Moderate buffering. pH should stay fairly steady.
From the utility that supplies yours: Metropolitan Water Dist. of So. Cal., which supplies Moulton Niguel Water District (2023–2026).
pH
Supplier's figure8.1–8.7
Typical 8.2
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From the utility that supplies yours: Metropolitan Water Dist. of So. Cal., which supplies Moulton Niguel Water District (2023–2026).
Total dissolved solids
Supplier's figure214–666 ppm
Typical 535 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: Metropolitan Water Dist. of So. Cal., which supplies Moulton Niguel Water District (2023–2026).
Who supplies Aliso Viejo, CA
Moulton Niguel Water District
Serves 66% of residents · Buys water from Joint Regional Water Supply System · 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.