Willowbrook, CA tap water
Supplied mostly by Gswc - Willowbrook, plus 4 other utilities. Here's what the water means for your fish.
Disinfectant
Chlorine or chloramine
Utilities here use chlorine or chloramine, depending on which one serves your address. Chlorine slowly gases off from standing water; chloramine doesn't.
Safety for fish and shrimp
Ammonia (with conditioner)
Estimate0.92–1.07 ppm (Worth knowing)
Typical 1 ppm
About 0.58 ppm is already in the water, and a conditioner frees about 0.41 ppm more when it breaks the chloramine apart. A cycled filter clears it within a day; a big water change in a new or very small tank adds more of it at once. Some conditioners also bind ammonia for a day or so.
Estimated from the chloramine level Los Angeles Department of Water and Power (LADWP) reports; California Water Board lab results (2024–2025).
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)
Supplier's figureUp to 7.5 ppm (Low)
Typically not detected
Not detected in testing, so water changes lower your tank's nitrate well.
From the utility that supplies yours: Metropolitan Water Dist. of So. Cal., which supplies Gswc - Willowbrook; California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal., which supplies Liberty Utilities - Compton; Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report (2023–2026).
Copper at home taps
0.06–0.53 ppm (Low)
Typical 0.07 ppm
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results; Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report (2023–2025).
Chlorine or chloramine at the tap
1.4–2 ppm
Typical 1.7 ppm
At tap levels, chlorine and chloramine are toxic to fish, shrimp and the bacteria in a filter. Water conditioners are made for this range.
Published by your utility: Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report.
Water chemistry
General hardness
Supplier's figure78–291 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 Gswc - Willowbrook; California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal., which supplies Liberty Utilities - Compton; Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report (2023–2026).
Carbonate hardness (alkalinity)
Supplier's figure68–210 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 Gswc - Willowbrook; California Water Board lab results; Metropolitan Water Dist. of So. Cal., which supplies Liberty Utilities - Compton; Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report; California Water Board lab results, measured before treatment (2023–2026).
pH
Supplier's figure7–8.7
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 Gswc - Willowbrook; California Water Board lab results; Metropolitan Water Dist. of So. Cal., which supplies Liberty Utilities - Compton; Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report; California Water Board lab results, measured before treatment (2023–2026).
Total dissolved solids
Supplier's figure187–666 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 Gswc - Willowbrook; California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal., which supplies Liberty Utilities - Compton; Los Angeles Department of Water and Power (LADWP)'s 2025 water quality report (2023–2026).
Who supplies Willowbrook, CA
Gswc - Willowbrook
Serves 44% of residents · Buys water from Metropolitan Water Dist. of So. Cal. · Chloramine
Suburban Water Systems - Sativa
Serves 31% of residents · Buys water from Liberty Utilities - Compton · Chloramine
Liberty Utilities - Compton
Serves 16% of residents · Buys water from Metropolitan Water Dist. of So. Cal. · Chloramine
- 2025 water quality report
Los Angeles Department of Water and Power (LADWP)
Serves 11% of residents · Lake or river water · Chloramine
Lynwood Park Mutual Water Co.
Serves 11% of residents · Groundwater (wells) · 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.
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Compiled by Shoal & Stem from public records. Free to cite with a link.