What Is pH?
by Brian Campbell
What is pH?
A simple definition of pH is that it measures how acidic or alkaline a solution is.
A more scientific definition is that pH indicates the concentration of hydrogen ions in a liquid. While a low pH indicates a higher concentration of hydrogen, a high pH indicates a lower hydrogen concentration.
For those with a background in chemistry, one can calculate the pH of any substance by using the pH calculation: pH = – log [H3O+].
This pH formula is not the only way to calculate water’s pH, however. This article will explain what affects water’s pH, the problems with acidic and alkaline water, and how to test pH in water at home.
What Changes the pH of Water?
Water has a neutral pH of 7, which indicates that it is neither acidic or alkaline. The pH scale ranges from 0 (very acidic) to 14 (very alkaline). It is normal for water to have a pH range of between 6.5 and 8.5 on the pH scale.
pH in water may fluctuate with differing environmental factors. Rainwater is naturally more acidic, and usually has a pH of around 5.65. But when this water falls through the air, it interacts with atmospheric carbon dioxide, which increases pH.
Once rainwater lands on the ground, the geology of the land will affect its pH once more. When this water seeps through layers of mineral-rich rock, it will become more alkaline. But if it is only exposed to igneous rock, like granite, it’s unlikely that its pH will change much at all.
Mining discharges and wastewater can also affect pH. pH in wastewater is typically neutral, but chemicals, pollutants and other contaminants in this water can cause it to become highly acidic or alkaline.
What Effect Does pH Have On Drinking Water?
The acidity or alkalinity of drinking water can have an effect on its makeup. While acidic water is more likely to contain metal contaminants, alkaline water typically has a high concentration of healthy minerals.
Alkaline water is said to be healthier than water with a neutral pH, as it prevents acidity in the body from causing chronic illnesses. However, there’s not much scientific evidence to back up these claims so far. What we do know is that water with a slightly higher pH of 8 to 8.5 is more likely to have a higher concentration of healthy minerals and electrolytes, like calcium, potassium and magnesium, which the human body needs to survive.
Acidic water, on the other hand, may corrode your teeth, so it is not recommended for consumption. Acid water is also more susceptible to metal leaching, so by drinking water with a low pH, one is more at risk of consuming dangerous levels of copper, lead, and similar contaminants.
Safe pH Range For Drinking Water
According to the Environmental Protection Agency (EPA), water’s safe pH range spans between 6.5 and 8.5 Anything higher or lower than this, and water is not recommended for drinking. The optimum pH for drinking water is 7.
Risks Associated With Unsafe pH Levels
Acidic water and alkaline water each pose their own specific risks.
Some of the risks associated with acidic water include:
Increased Metals Intake
Water with a lower pH is more likely to grab onto heavy metals like copper, lead, arsenic, zinc, and chromium. Drinking acidic water puts you more at risk of consuming a higher concentration of these metals. In the long term, this may lead to dangerous conditions like toxicity and heavy metal poisoning.
Damage to Teeth
Your overall dental health may be affected by drinking acidic water. Because water with a low pH is more corrosive, it is likely to increase the risk of decay of the tooth enamel. The tooth enamel is important to protect the inner layers of the tooth from damage and keep teeth looking white. Decayed tooth enamel is more susceptible to cavities and infections.
The corrosive properties of acidic water may also damage your home’s plumbing system. Over time, water with a low pH can dissolve metal pipes, causing heavy metals to leach into your water. Acidic water can also cause pipes to wear away, resulting in leaks that may be expensive to repair.
Some of the risks of drinking alkaline water include:
Lowers Stomach Acidity
Alkaline water may lower pH in the stomach. This could lower the stomach’s natural acid, which is needed to kill bacteria and other pathogens, preventing them from passing into the bloodstream.
Too much alkaline water can result in a condition called metabolic alkalosis, which imbalances the body’s normal pH. With metabolic alkalosis, you may experience symptoms like vomiting, nausea, muscle twitching, hand tremors, and confusion.
Poor bone health
Alkalosis has also been known to decrease the body’s free calcium, which can affect bone health. Additionally, low levels of free calcium can slow down heart rate and cause muscle spasms.
How to Test Water’s pH
In a laboratory setting, pH meters are typically used to give an accurate reading of pH in water. You can buy a pH meter online, but they can be on the more expensive side.
A more affordable alternative is to purchase a single-use at home pH test kit. pH test kits come with strips that one can dip into a water sample. The strip will turn a certain color to indicate how acid or alkaline the water is.
One can buy different pH kits that are designed to work with specific pH ranges. When dealing with particularly acidic or alkaline water, make sure the pH kit is designed to work with this pH range. This is the better option than buying a testing kit that ranges from 1 to 14, as it may be more difficult to get an accurate result based on the test strip’s color hue.
pH test strips can be handy for initially assessing water, and testing it again after treating water to increase or decrease its pH.
In short, if using water for drinking, one should make sure it has a pH of between 6.5 and 8.5; preferably as close to 7 as possible. Any higher or lower than this, and the water is not safe to drink.
Brian Campbell is the founder of WaterFilterGuru.com, where he blogs about all things water quality.