Gahanna, OH tap water
Supplied mostly by Columbus Water & Power (CWP), plus 1 other utility. Here's what the 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 (2018).
Nitrate (NO₃)
5.8–28 ppm (Low)
Typical 5.8 ppm
Water changes can't take your tank's nitrate below this level.
From Columbus Water & Power (CWP)'s 2025 water quality report; Columbus Public Water System, which supplies Gahanna City PWS.
Copper at home taps (first draw)
0.05 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: Columbus Water & Power (CWP)'s 2025 water quality report.
Chlorine or chloramine at the tap
0.9–1.6 ppm
Typical 1.4 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: Columbus Water & Power (CWP)'s 2025 water quality report.
Water chemistry
General hardness
85–132 ppm
Typical 115 ppm
Moderately soft to medium. Suits most community fish and plants.
From Columbus Water & Power (CWP)'s 2025 water quality report; Columbus Public Water System, which supplies Gahanna City PWS.
Carbonate hardness (alkalinity)
35–74 ppm
Typical 48 ppm
Moderate buffering. pH should stay fairly steady.
From Columbus Water & Power (CWP)'s 2025 water quality report; Columbus Public Water System, which supplies Gahanna City PWS.
pH
7.8–7.9
Typical 7.8
Most community fish do well here. Stable water matters more than the exact number.
From Columbus Water & Power (CWP)'s 2025 water quality report; Columbus Public Water System, which supplies Gahanna City PWS.
Total dissolved solids
313 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 Columbus Water & Power (CWP)'s 2025 water quality report; Columbus Public Water System, which supplies Gahanna City PWS.
- Columbus Water & Power (CWP) and Gahanna City PWS add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
- Columbus Water & Power (CWP) and Gahanna City PWS soften their water at the plant, so it may be softer than the local groundwater.
Who supplies Gahanna, OH
- 2025 water quality report
Columbus Water & Power (CWP)
Serves 51% of residents · Lake or river water · Chlorine
Gahanna City PWS
Serves 50% of residents · Buys water from Columbus Public Water System · 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.
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Compiled by Shoal & Stem from public records. Free to cite with a link.