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What Does Low pH Mean? Is It Safe for My Household?

Copper pipe with corrosion

Low pH water is slightly acidic. That means it’s more likely to cause corrosion and leach metals from pipes and plumbing fixtures. 

Health wise, the biggest concern with low pH water comes from homes with copper pipes. Acidic water can pull copper from the pipes, carrying those metals into your drinking water. While small amounts of copper are an essential part of our diet, significant, long-term exposure can cause health problems

Learn more about your water quality and whether it’s time to treat your water below:

  • What Does Low pH Mean?
  • Is Low pH Safe for Drinking Water?
  • What Causes Acidic Water? 
  • What Are the Signs of Acidic Water?
  • Correcting pH and Treating Acidic Water

What Does Low pH Mean?

The term “pH” is used to measure the acidity or alkalinity of water and other liquid solutions. The pH scale ranges from 0 to 14. Pure water has a pH of 7 and is considered neutral. 

Lower pH numbers indicate a stronger acid, while higher pH numbers indicate a stronger base (alkalinity).  Anything lower than 7 is considered acidic, and anything over 7 is basic.

The lower a number is, the stronger the acid. For example, milk has a pH of 6, coffee has a pH of 5, and lemon juice has a pH of 2. 

Hand holding pH scale under water

As you can see, low pH or “acidic” solutions are not always dangerous, many low pH liquids (AKA acids) are perfectly natural and safe.

Is Low pH Safe for Drinking Water?

The pH of water isn’t a quality that’s regulated by the Environmental Protection Agency (EPA). Generally, however, the agency recommends that water supplies should fall between 6.5 and 8.5 pH.

Water that falls outside those ranges isn’t necessarily unsafe. But it might have an unpleasant taste or be corrosive to plumbing systems and appliances.

When water tests below 6.5 pH, it could be an indicator that pollutants are present in the water. Lower pH isn’t an issue itself– but certain pollutants that enter the water as a result of its corrosive properties can make the water unsafe to drink. 

As water becomes more acidic, it has a greater tendency to leach metal ions from pipes, plumbing fixtures, and aquifers. Too many heavy metals, like copper and lead, can make your water unsafe to drink.

What Causes Acidic Water?

So, if water is naturally neutral, how does it change into acidic water? Low pH water can be caused by a number of sources, including acid rain, certain rock formations, and plant decomposition. 

However, acidic water can also be caused by chemical runoff and other pollution. Low pH water may be found near power plants, landfills, mining sites, and large animal farms.

What Are the Signs of Acidic Water?

If your water has low pH, you may notice a metallic or sour taste when you drink it. You may also see blue-green staining or rust-colored staining on your faucets, drains, and other fixtures. This color is caused by the very tiny flecks of copper that were stripped from your plumbing being deposited onto the surface of your sink. Then as the water dries, the copper is left there to oxidize by the air which changes it to green. Because low pH water can leach metals and cause corrosion, it can even lead to leaks in your plumbing if it eats all the way through the wall of your pipe. 

Signs of low pH (acid) water:

  • Metallic taste
  • Sour taste
  • Red or rust-colored staining (with galvanized steel or cast-iron plumbing)
  • Blue/green staining (with copper plumbing)
  • Plumbing leaks 

To test for exact results – and to find out if your water has other metals or pollutants – contact your authorized WaterCare Dealer for reliable home water testing. Our WaterCare experts test for pH and various metals, such as lead and copper, that can be provided in your home at no cost. 

Correcting pH and Treating Acid Water

Homeowners who wish to treat acid water have a relatively easy answer to protect their entire home and family. 

Our CareClear Pro Acid Neutralizer filter works by adding calcite to neutralize the water as soon as it enters your home. Calcite is a natural type of rock that helps raise the pH level of your water as it dissolves. As water flows through the filter, trace amounts of calcite dissolve into the water, neutralizing the pH levels. Balancing filters work best when the water has a pH of 5.5 or higher.

For water that has pH levels even lower than 5.5, your WaterCare dealer may recommend blending the calcite with another mineral called corosex. This mixture has the strength to help boost really low pH levels in the 4.0-5.0 range back up to the more balanced neutral levels.

Because the calcite (and corosex) inside sacrifices itself to bring your water back to neutral, it is necessary to have a WaterCare dealer come back regularly to refill the media to make sure your CareClear Pro continues to offer up the protection you expect from the filter.


Supplemental Filters. As discussed above, sometimes water gets a low pH due to the presence of chemicals or pollutants in the ground or aquifer. If you have any concerns as to any industrial chemicals traveling in your water, like PFAS, an additional filter would be necessary to reduce the presence of that chemical to ensure that your family is not consuming it. 

If water testing reveals other chemical issues are present, you may want to add extra contaminant reduction or a reverse osmosis system to remove other water impurities and make sure your drinking water is the best it can possibly be.

If you are concerned about acidic water in your home, call the water treatment specialists at your WaterCare authorized dealer. We can provide free water testing and design a water system for whole home health and safety.