Maplewood, MN tap water
Supplied mostly by Saint Paul Regional Water Services, 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 about 0.78 ppm of ammonia here. Some utilities switch to plain chlorine for a few weeks a year.
Safety for fish and shrimp
Ammonia (with conditioner)
Estimate0.73–0.85 ppm (Worth knowing)
Typical 0.78 ppm
This is what a conditioner frees 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 Saint Paul Regional Water Services reports (2025).
Nitrate (NO₃)
0.7 ppm (Low)
Low, so water changes lower your tank's nitrate well.
Published by your utility: Saint Paul Regional Water Services' 2025 water quality report.
Copper at home taps (first draw)
Up to 0.14 ppm (Low)
The 90th percentile of first-draw samples from homes: water that sat in household pipes for at least six hours.
Low. Water that sits in household pipes overnight can carry more than this.
Published by your utility: Saint Paul Regional Water Services' 2025 water quality report.
Chlorine or chloramine at the tap
3–3.5 ppm
Typical 3.2 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: Saint Paul Regional Water Services' 2025 water quality report.
Water chemistry
General hardness
90 ppm
Moderately soft to medium. Suits most community fish and plants.
Published by your utility: Saint Paul Regional Water Services' website.
Carbonate hardness (alkalinity)
55–57 ppm
Typical 56 ppm
Moderate buffering. pH should stay fairly steady.
From EPA monitoring data (2012–2019).
pH
8.9–9
Typical 8.9
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From EPA monitoring data (2012–2019).
- Saint Paul Regional Water Services softens its water at the plant, so it may be softer than the local groundwater.
Who supplies Maplewood, MN
- 2025 water quality report
Saint Paul Regional Water Services
Serves 95% of residents · Lake or river water · Chloramine
North Saint Paul
Serves 6% of residents · Groundwater (wells) · Disinfectant not listed
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.