Rochester, MN tap water
Supplied by Rochester Public Utilities (RPU). 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 EPA monitoring data (2012–2016).
Nitrate (NO₃)
Up to 0.8 ppm (Low)
Typical 0.8 ppm
Low, so water changes lower your tank's nitrate well.
Published by your utility: Rochester Public Utilities (RPU)'s 2025 water quality report.
Chlorine or chloramine at the tap
0.9–1.1 ppm
Typical 1 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: Rochester Public Utilities (RPU)'s 2025 water quality report.
Water chemistry
General hardness
280–291 ppm
Typical 280 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
Published by your utility: Rochester Public Utilities (RPU)'s website.
Carbonate hardness (alkalinity)
Area estimate236–291 ppm
Typical 266 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
Area estimate from nearby wells: USGS well samples in your county (2003–2014).
pH
Area estimate6.9–7.3
Typical 7.1
Most community fish do well here. Stable water matters more than the exact number.
Area estimate from nearby wells: USGS well samples in your county (2003–2014).
Total dissolved solids
Area estimate282–400 ppm
Typical 327 ppm
A rough measure of everything dissolved in the water. RO water reads near 0, so TDS is a quick way to compare waters.
Area estimate from nearby wells: USGS well samples in your county (2003–2014).
- Rochester Public Utilities (RPU) adds phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Rochester, MN
- 2025 water quality report
Rochester Public Utilities (RPU)
Serves 99% 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.