Longmont, CO tap water
Supplied by City of Longmont. 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 (2012–2014).
Nitrate (NO₃)
Not detected (Low)
Not detected in testing, so water changes lower your tank's nitrate well.
From EPA monitoring data (2012–2019).
Copper at home taps (first draw)
0.05–0.08 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: City of Longmont's water quality report.
Chlorine or chloramine at the tap
0.6–1.6 ppm
Typical 1.1 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: City of Longmont's water quality report.
Water chemistry
General hardness
19–25 ppm
Typical 22 ppm
Soft. Good for tetras, rasboras and most shrimp. Livebearers, snails and African cichlids prefer harder water.
Published by your utility: City of Longmont's water quality report.
Carbonate hardness (alkalinity)
25–34 ppm
Typical 30 ppm
Little buffering. pH can drop quickly between water changes, especially with CO₂ or an older tank.
Published by your utility: City of Longmont's water quality report.
pH
8–8.6
Typical 8.3
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
Published by your utility: City of Longmont's water quality report.
Who supplies Longmont, CO
- Water quality report
City of Longmont
Serves 96% of residents · Lake or river water · 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.