Everything You Need To Know About Water Acidity And Its Impact On Your Family

Do you know from ocean acidification to greenish stains in your wash basin, all are the result of acidity in water? Checkout this improved Urban guide to counter its effects and protect your family

What is acidity in water?

Water that has a pH level below 7 on a pH scale is considered to be a acidic in nature. Acidity in water occurs when in a sample we have: No of Hydrogen(H+) ions > No of Hydroxyl(OH-) ions. This lowers the pH of water. As we know a water sample is:
⦁Acidic  if --> pH < 7  , with 0 being the most acidic
⦁Alkaline if -->  pH > 7 , with 14 being the most ⦁alkaline     
⦁Neutral if --> pH = 7  , with 7 being the most balanced⦁ pH Solution
Since the pH is represented on a logarithmic scale (with a base 10). A sample with a pH 4 is 10 times more acidic than a sample with a pH 5. And hence pH 3 would be 100 times more acidic than pH 5.

The lower we move down the scale, the more acidic the solution is with 0 being very acidic.

Is it possible for a water sample to have both acidity and alkalinity?

Yes, it is possible. As we know acidic water has more no of hydrogen(H+) ions than hydroxyl(OH-) ions. Low pH water are acidic in nature. Whereas alkalinity on the other hand is the measure of the buffering capacity of a solution. Alkalinity of a solution is defined as the amount of acid that a solution can neutralize before changing its pH level.

A sample could be acidic but still resist change in its pH (say from pH 3 to pH 2). This resistance is buffering capacity or alkalinity and it exists at all pH level no matter how low it may be.

Why concern ourselves with acidity in water? How is it relevant to you?

Acid water is very corrosive in nature. Water acidity not only affects our water supply line but also our body if consumed. It is so corrosive that a sample of pH 1 or 2 can leach metals out of metal pipes. 

Water Hardness and Acidity

Due to its corrosive nature acidic water tends to increase water hardness. This is because when it flows through the terrain, being corrosive in nature dissolves a lot of minerals in the process through leaching.

Acidity and Water Turbidity

Since water at low pH is corrosive in nature it corrode and dissolves a lot of minerals in its path of flow. This results in increasing the turbidity of water because of the load it carries along the way. 

Greenish stains in wash basin

When pH is low, water will corrode away the copper from the water supply pipeline. As this water drain into your wash basin, it may deposit a layer of it in it. If you happen to observe greenish stains in your wash basin. This can clearly illustrate that you water supply is acidic in nature and it is leaching away the metals of your supply pipeline.

Origin: What causes acidity in water?


Rainwater is slightly acidic in nature. It is so because water when falls dissolves a lot of minerals in the process. This makes it acidic in nature.

Check out the effects of Acid Rain in detail. Carbon dioxide when dissolved in water forms a weak carbonic acid. The increase in global warming makes sure there is abundant of carbon dioxide in our atmosphere. This is the main reason for Ocean Acidification.


Water left stranded in abandoned mines could be very acidic in nature. This is because mines are rich in minerals. These minerals dissolve little water to form a concentrated acidic water.

Oil spills and chemical dumps are other causes contributing to further raising the acidity in water. 

Urban Water Acidity Standards 

Urban Water Hardness Standards

U.S. Department of Interior and the Water Quality Association categorize hardness level for water as shown below :

Water of both extremes (alkaline and acidic) should be avoided for consumption. 

There are certain recommendations regarding the pH of drinking water.

United States Environmental Protection Agency recommends:
Drinking water pH : Should lie between 6.5 - 8.5 on a scale ranging from 0 to 14.

The standard for the hardness level may differ slightly for different guidelines issued by many organizations but the standards remain more or less the same.



Visually it is impossible to detect acidic water from non acidic one. Instead a pH paper is used to determine the level of acidity in water.

Touch is another way to detect but remember high acidic water is very corrosive in nature. Always avoid touching such a solution with bare hands. 


 pH Tester are available in market.

Urban water acidity treatment


Calcite is commonly used to raise the pH of the water. Calcite is white crushed marble. It is rich in calcium and acts as a base. It is deployed at the entry point of your household water supply system.

Georgia Marble is one of the best calcite for use. 

Reasons to use


⦁ It is inexpensive

⦁ Self Limiting. Do not raise pH beyond 7 

⦁ Is slow to act. Need to remain in contact with water for quite sometime to act.  

⦁ Can raise pH up to 1 pH level only.

⦁ Raise little water hardness by releasing

Magnesium oxide

Magnesium oxide is generally known and sold under the tag FLOMAG and Corsex. It neutralizes acidity by getting rid of the free carbon dioxide in water. 

Reasons to use


⦁ It is not costly

⦁ Act fast and rapidly raise the pH of water.

⦁ Due to rapid speed of reaction could raise water pH to an undesired level increasing hardness level.

Recommendation: A combination of calcite and Corsex is used together to raise the pH of water. This is because Corsex, unlike calcite reacts quickly. This could drastically raise the pH of water. The ratio for use is generally 80:20 of that of calcite and Corsex.

Also using too much magnesium oxide can raise the level of magnesium in water. This could raise the hardness level in water.

Soda ash and caustic soda

Calcite and Corsex can act as an acid neutralizer if the pH level is not too low. Highly acidic water needs more complex solution. It needs a chemical injection system to neutralize the water. This chemical pH adjuster called soda ash is a form of sodium carbonate. Peristaltic pump technology is used to inject soda ash into water.
If the pH is too low, caustic soda is a more viable option. Since it has an alkalinity level of 14, can easily neutralize the high acidity in water.

Reasons to use


⦁ Can raise pH of highly acidic water soultions.

⦁ Act rapidly to neutralize.

⦁ Do not raise hardness in water.

 ⦁ High maintenance required.

 ⦁ Needs proper time to work.

 ⦁ One must be precise about the quantity to be used.

Recommendations for acid neutralizers

They do not require frequent maintenance. But due to usage and exhaustion may require refilling on an annual basis. The amount of neutralizer needed depends on three factors:

⦁ Rate of flow of water in home water supply.
⦁ Amount of water(in gallons) to be neutralized
⦁ The pH level of water for determining the type of base to use to neutralize water acidity.



 Ocean acidification

Ocean Acidification is the decrease in the pH of an ocean. Earlier humans were of the notion that something as big as an ocean could never be affected by human activities. But recent studies have shown that the increase in greenhouse effect is causing the acidification. Greenhouse gases such as Carbon dioxide, Sulfur dioxide on abundance dissolve in rainwater and fall onto the ocean.

This change in pH is highly devastating for the ocean inhabitants. They are so sensitive towards change in pH that even a drop of 1 or 2 pH can deplete a variety of aquatic life. The dangers of ocean acidification has even surpasses that posed by the plastics.

Acid Rain

Acidic precipitation can be caused by both natural (volcanoes) and man made ( a long list of air pollution including vehicle and factory emissions) sources.

Rain(or snow) on falling down dissolves a number of air pollutants to form a weak acid and falls as acidic rain. Acid rain works in a two way process : dissolution and alteration.

Acid rain is highly corrosive and can leach away limestones and marble buildings. One of the leading factors of ocean acidification. It is harmful to human skin and can cause rashes and itching sensation.


Effects of the metals if consumed along with the acidic water is many. Some of them are summed below.

⦁ Abundance of copper can lead to kidney damage in humans. Stomach ache and nausea are other health risks.

⦁ The leaching of metals often leads to a gastrointestinal problems.

⦁ Overexposure to zinc from pipes, can cause nausea, diarrhea, and vomiting.

⦁ Heavy metals like lead is an extremely dangerous metal, especially for children. Lead exposure can cause cognitive impairment, memory problems, stunted development, and seizures.

The problems are many it's important to take note of them and improve our urban water quality for consumption.