Sioux Falls, SD tap water
Supplied mostly by City of Sioux Falls Water Division, plus 2 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
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From EPA monitoring data (2018–2019).
Nitrate (NO₃)
Up to 5.3 ppm (Low)
Typical 2 ppm
Low, so water changes lower your tank's nitrate well.
From City of Sioux Falls Water Division's 2025 water quality report; Lewis and Clark Regional Water Syste, which supplies Lincoln County Rural Water System; EPA monitoring data (2017–2025).
Copper at home taps (first draw)
0.1 ppm (Worth knowing)
The 90th percentile of first-draw samples from homes: water that sat in household pipes for at least six hours.
Shrimp and snails are sensitive to copper. Water that sits in household pipes picks up the most; it drops once the tap has run for a minute.
Published by your utility: City of Sioux Falls Water Division's 2025 water quality report.
Chlorine or chloramine at the tap
2.4–2.8 ppm
Typical 2.6 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: City of Sioux Falls Water Division's 2025 water quality report.
Water chemistry
General hardness
168–250 ppm
Typical 168 ppm
Moderately hard. Great for livebearers, and most community fish adapt.
Published by your utility: City of Sioux Falls Water Division's 2025 water quality report.
Carbonate hardness (alkalinity)
54–65 ppm
Typical 54 ppm
Moderate buffering. pH should stay fairly steady.
Published by your utility: City of Sioux Falls Water Division's 2025 water quality report.
pH
8.3–8.8
Typical 8.3
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
Published by your utility: City of Sioux Falls Water Division's 2025 water quality report.
- City of Sioux Falls Water Division, Lincoln County Rural Water System and Minnehaha Community Water Corp add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
- City of Sioux Falls Water Division, Lincoln County Rural Water System and Minnehaha Community Water Corp soften their water at the plant, so it may be softer than the local groundwater.
Who supplies Sioux Falls, SD
- 2025 water quality report
City of Sioux Falls Water Division
Serves 82% of residents · Lake or river water · Chlorine
Lincoln County Rural Water System
Serves 8% of residents · Buys water from Lewis and Clark Regional Water Syste · Chlorine
Minnehaha Community Water Corp
Serves 5% of residents · Groundwater (wells) · 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.
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.