Mount Prospect, IL tap water
Supplied mostly by Mount Prospect, plus 2 other utilities. 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
Nitrate (NO₃)
Supplier's figure1.4–1.6 ppm (Low)
Typical 1.6 ppm
Low, so water changes lower your tank's nitrate well.
From the utility that supplies yours: Chicago, which supplies Mount Prospect; Wilmette, which supplies Illinois American Water – Chicago Suburban; Chicago, which supplies Illinois American Water – Waycinden (2012–2025).
Water chemistry
General hardness
Supplier's figure130–151 ppm
Typical 140 ppm
Moderately soft to medium. Suits most community fish and plants.
From the utility that supplies yours: Chicago, which supplies Mount Prospect; Chicago, which supplies Illinois American Water – Waycinden.
Carbonate hardness (alkalinity)
Supplier's figure110–126 ppm
Typical 121 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From the utility that supplies yours: Chicago, which supplies Mount Prospect; Wilmette, which supplies Illinois American Water – Chicago Suburban; Chicago, which supplies Illinois American Water – Waycinden (2017–2019).
pH
Supplier's figure8.2–9.4
Typical 8.8
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From the utility that supplies yours: Chicago, which supplies Mount Prospect; Chicago, which supplies Illinois American Water – Waycinden (2025).
- Mount Prospect, Illinois American Water – Chicago Suburban and Illinois American Water – Waycinden add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Mount Prospect, IL
Mount Prospect
Serves 73% of residents · Buys water from Northwest Suburban Municipal Jawa · Chlorine
Illinois American Water – Chicago Suburban
Serves 21% of residents · Buys water from Glenview · Chlorine
Illinois American Water – Waycinden
Serves 6% of residents · Buys water from Des Plaines · 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.