Blackwells Mills, NJ tap water
Supplied mostly by NJ American Water - Raritan System, plus 1 other utility. Here's what the water means for your fish.
Disinfectant
Chloramine
Your water is treated with chloramine. Unlike chlorine, it doesn't gas off when water sits out, and many pitcher and fridge filters aren't rated to remove it. Conditioners that list chloramine on the label break it apart, which frees about 0.29 ppm of ammonia here. Some utilities switch to plain chlorine for a few weeks a year.
Safety for fish and shrimp
Ammonia (with conditioner)
EstimateUp to 0.97 ppm (Low)
Typical 0.29 ppm
This is what a conditioner frees when it breaks the chloramine apart. A cycled filter clears it within a day.
Estimated from the chloramine level NJ American Water - Raritan System reports (2025).
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From EPA monitoring data (2012–2019).
Nitrate (NO₃)
3.1–18 ppm (Low)
Typical 8.2 ppm
Water changes can't take your tank's nitrate below this level.
From EPA monitoring data; New Jersey American Water – Raritan and North Brunswick W Dept and South Brunswick Twp W Di and New Brunswick W Dept, which supplies Franklin Township Dept of Public Works (2012–2019).
Chlorine or chloramine at the tap
0–4 ppm
Typical 1.2 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: NJ American Water - Raritan System's 2025 water quality report.
Water chemistry
General hardness
90–222 ppm
Typical 156 ppm
Moderately hard. Great for livebearers, and most community fish adapt.
From NJ American Water - Raritan System's website; New Jersey American Water – Raritan, which supplies Franklin Township Dept of Public Works.
Carbonate hardness (alkalinity)
0–180 ppm
Typical 127 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From EPA monitoring data (2012–2019).
pH
5.8–8.5
Typical 7.5
Most community fish do well here. Stable water matters more than the exact number.
From NJ American Water - Raritan System's website; New Jersey American Water – Raritan and North Brunswick W Dept and South Brunswick Twp W Di and New Brunswick W Dept, which supplies Franklin Township Dept of Public Works (2012–2019).
- NJ American Water - Raritan System and Franklin Township Dept of Public Works add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
- NJ American Water - Raritan System and Franklin Township Dept of Public Works soften their water at the plant, so it may be softer than the local groundwater.
Who supplies Blackwells Mills, NJ
- 2025 water quality report
NJ American Water - Raritan System
Serves 73% of residents · Lake or river water · Chloramine
Franklin Township Dept of Public Works
Serves 7% of residents · Buys water from New Jersey American Water – Raritan · 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.