WATER QUALITYHow to Treat Low pH Acidic Water

April 14, 2022

Acidic water is very corrosive and causes plumbing damage, this may cause major expenses you might not have been planning for. It can also be a serious health concern if left unresolved. Acidic water, or water with a low pH value, also leaches heavy metals from eroding pipes, exposing your water to copper, zinc, and even lead. For many well owners, acidic water is a serious water quality problem. So how should you treat low pH acidic water?

What’s Acidic Water?

Acidic water has a low pH value. Water with a pH of 6.5 or less, on a scale from 1-14, is acidic. 7 is neutral pH in water. Acidic water is a natural occurrence. Rain is naturally slightly acidic. It can increase or decrease depending on environmental factors, what it comes into contact with on and in the ground and human causes. Water with a pH 7.5 or higher is alkaline water. Alkaline water has more mineral content.

How to Treat Low pH Acidic Water
Acidic water has a low pH value. Water with a pH of 6.5 or less, on a scale from 1-14, is acidic. 7 is neutral pH in water.

Why is My Water at Home Acidic?

Rain is naturally acidic because of it is in contact with and has carbon dioxide in it. Water evaporates at times in the natural water cycle. Evaporation and condensation is a natural filtering or purification. Distilling water or water softening gets the same result, of taking minerals out of water and decreasing the pH value.

When precipitation falls, the normal pH of rain or snow is 5.6. It’s actually a slight carbonic acid. Once the precipitation is on the ground, it can run through soil, rock, salt, mineral, man-made material, go into bodies of water and these factors change the water’s pH.

How Does Acidic Water Damage Plumbing?

Acidic water can damage plumbing, causing corrosion, leaks and leaches. The damage can become dangerous to health and expensive to repair.

Acidic water dissolves copper. Blue-green corrosion on copper pipes is from acidic water. This can also cause stains and wear on fixtures and other components. Acidic water can damage appliances and water heaters. Higher temperatures increases the effects of acidic water.

If left ignored, tiny holes, cracks and leaks can form, leading to more damage and problems. For instance, if these leakages arise behind a wall, significant flooding can occur. Replacing plumbing can cost as much as 20% of your house’s value, so finding and resolving acid water as soon as possible is vital.

Leaching is another major issue with acidic water. Acidic water can leach, or take small but steady amounts of metal out of pipes or other components in a well or public water supply route. This water can have iron, copper, lead, zinc or other metal content in it. This is hazardous, ranging from unpleasant smells and taste to very serious health effects.

Is Acidic Water Bad to Drink?

This depends on how far the pH level is from neutral and the frequency or duration of the consumption of the water. The short answer, though, is yes, acidic water is unhealthy to drink or consume.

If your water has too much metal in it, symptoms and illnesses can include nausea, diarrhea and other internal and digestive problems. Kidney stones, gall bladder diseases, neurological problems and other kidney, liver and organ diseases can result from long-term exposure to acidic water. Lead in water is dangerous, especially to children. Lead poisoning symptoms include stunted growth, seizures, cognitive problems or disorders, hypertension, nervous system disorders, kidney failure, strokes, cancer and pregnancy complications or major problems.

How Can I Treat Acidic Water?

The pH level in your home water will tell you what options are best for treating it.


A common way to treat acidic water is with an acid neutralizer which usually contains calcite as the primary material. Calcite increases the pH in water before it’s in your home and plumbing.  Calcite is smashed white marble rock that’s abundant in calcium and very high in alkalinity. Acid neutralizer storage tanks are installed at the water’s point of entry at your property. The tanks hold calcite. When the water goes into the tank it dissolves some of the calcite into it.

Along with being economical, calcite is self-limiting. Only so much calcite will be dissolved at a time, so it will raise the pH only a predictable amount – about 1 pH point – and stop. For instance, if your water has a 6 pH, using calcite will raise the pH to about 7. There’s no chance of turning water too alkaline.

Nonetheless, calcite has fundamental limitations. It needs the right amount of time to work. If water goes through the tank at a rapid speed, the pH adjustment will be very little.

Magnesium Oxide

If water has higher acidity, or lower pH, calcite will need more power to help it. Magnesium oxide elevates pH levels by countering the carbon dioxide in water. Calcite and magnesium oxide can be used together to cause a larger pH change.

However, magnesium oxide isn’t self-limiting. It can overdo the pH change. It’s generally recommended in most cases to use the right ratio of 80-90% calcite and 10-20% magnesium oxide. Too much magnesium oxide can raise pH levels too much and have health side effects as well.

For Lower pH Levels

Acidic water with pH readings lower than about 5.5 need solutions stronger than magnesium oxide or calcite. Soda ash or caustic soda are used in acidic water in these pH ranges.

Soda ash is used in a pump and infusion method to raise water’s pH. Chemical injection methods such as this take more maintenance and steady upkeep to operate correctly.

In water with a pH level in the fours or lower, the only acid neutralizer option is caustic soda. Caustic soda as a 14 pH. It is potent enough to change acidic water to a safe range.


South End Water Filtration specializes in HALO Water Filter products including the HALO H2 Zero Whole Home Water Filter. HALO systems solve hard water problems, give your family clear, great-tasting water and are totally maintenance free. We’re just a click away to help and answer any questions. South End Plumbing and South End Water Filtration will give you a free estimate. Call us at 704-486-1988 or contact us online to schedule a visit.