Houston, TX tap water
Supplied by City of Houston. Here's what its 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 0.36 ppm of ammonia here. Some utilities switch to plain chlorine for a few weeks a year.
Safety for fish and shrimp
Ammonia (with conditioner)
Estimate0.01–1.31 ppm (Low)
Typical 0.36 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 City of Houston reports (2024).
Nitrite (NO₂)
Up to 0.13 ppm (Worth knowing)
Typical 0.13 ppm
Some nitrite shows up in this tap water, which can happen in chloramine systems, and it goes into the tank with each water change.
Published by your utility: City of Houston's 2024 water quality report.
Nitrate (NO₃)
Up to 4.2 ppm (Low)
Typical 1.1 ppm
Low, so water changes lower your tank's nitrate well.
Published by your utility: City of Houston's 2024 water quality report.
Copper at home taps (first draw)
0.05–0.37 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 Houston's 2024 water quality report.
Chlorine or chloramine at the tap
0–5.4 ppm
Typical 1.5 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 Houston's 2024 water quality report.
Water chemistry
General hardness
43–183 ppm
Typical 118 ppm
Moderately soft to medium. Suits most community fish and plants.
Published by your utility: City of Houston's 2024 water quality report.
Carbonate hardness (alkalinity)
85–193 ppm
Typical 170 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From EPA monitoring data (2012–2019).
pH
6.7–9
Typical 7.8
Most community fish do well here. Stable water matters more than the exact number.
Published by your utility: City of Houston's 2024 water quality report.
Total dissolved solids
144–321 ppm
Typical 203 ppm
A rough measure of everything dissolved in the water. RO water reads near 0, so TDS is a quick way to compare waters.
Published by your utility: City of Houston's 2024 water quality report.
- City of Houston softens its water at the plant, so it may be softer than the local groundwater.
Who supplies Houston, TX
- 2024 water quality report
City of Houston
Serves 90% of residents · Lake or river water · 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.