Merced, CA tap water
Supplied by City of Merced. Here's what its water means for your fish.
Disinfectant
Chlorine
Your water is treated with chlorine. It slowly gases off from standing water, and any water conditioner removes it.
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)
6.6 ppm (Low)
Water changes can't take your tank's nitrate below this level.
From California Water Board lab results (2023–2026).
Copper at home taps
0.06 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
64–240 ppm
Typical 88 ppm
Moderately soft to medium. Suits most community fish and plants.
From California Water Board lab results, measured before treatment (2023–2026).
Carbonate hardness (alkalinity)
93–240 ppm
Typical 130 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment (2023–2026).
pH
7.7–8
Typical 7.9
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results, measured before treatment (2023–2026).
Total dissolved solids
210–400 ppm
Typical 240 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 (2023–2026).
Who supplies Merced, CA
City of Merced
Serves 94% 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.
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.