pH is a determined value based on a defined scale, just like a temperature scale. So, the pH value of water is not a physical parameter that you can measure as a concentration or in a quantity. It is a figure between 0 and 14 that defines how acidic or basic a body of water is along a logarithmic scale. The lower the number, the water is more acidic. The higher the number, the more basic it will be. A pH of 7 is considered neutral. All Kind of water purifier filter water up to drinkable PH Level
pH is a measurement of electrically charged particles in a substance. It indicates how acidic or alkaline (basic) that substance is. The pH scale ranges from 0 to 14:
- Acidic water has a pH lower than 7. The most acidic substances have a pH of 0. Battery acid falls into this category.
- Alkaline water has a pH of 8 or above. The most alkaline substances, such as lye, have a pH of 14.
- Pure water has a pH of 7 and is considered “neutral” because it has neither acidic nor basic qualities.
pH value for water
Generally, the pH value is a good indicator of whether water is hard or soft. The pH of pure water is 7 which is neutral. Basically, water with a pH lower than 7 is considered acidic, and a pH greater than 7 is considered basic. The normal range of pH of surface water systems is 6.5 to 8.5, and the pH range of groundwater systems is between 6 to 8.5. Alkalinity is a measure of the capacity of the water to resist a change in pH that makes the water more acidic. The measurement of alkalinity and pH is needed to be calculated for the corrosiveness of the water.
|Type of water||pH level|
|Tap water||Varies; typically about 7.5|
|Distilled reverse osmosis water||5 to 7|
|Common bottled waters||6.5 to 7.5|
|Bottled waters labeled as alkaline||8 to 9|
|Ocean water||About 8|
|Acid rain||5 to 5.5|
How to measure pH
By using pH meter
- Calibrate the probe and meter by checking the manufacturer specifications. You have to calibrate the meter by testing it in a substance with a known pH rating. You can then adjust the meter according to it. If you are going to test water away from a lab, you have to perform this calibration several hours before you take the meter to the field. Rinse the probe with double deionized water before you use it. Dry it off with a clean tissue.
- Collect a sample of the water in a clean container. The water sample should be deep enough to cover up the tip of the electrode. Let the sample be there for a moment so the temperature can be stabilized, then measure the temperature of the sample using a thermometer.
- Adjust the meter to match the sample temperature. The probe’s sensitivity will be affected by the temperature of the water, and so the reading of the meter may not be accurate if you do not input the temperature data. The pH of the water will also be affected by the water’s temperature because pure water has a lower pH at higher temperatures and a higher pH at lower temperatures
- Put the probe into the sample and let the meter to come to equilibrium. The meter will reach equilibrium when the measurement becomes steady.
- Now read the pH measurement of the sample. Your pH meter will provide a reading on the scale of 0-14. If the water is pure, it should read close to 7.
A pH reading lower than 7 means that the water is acidic, and a reading higher than 7 indicates that the water is basic.
By using litmus paper
Litmus papers are strips of paper that contain an acid or a base. The most common of these are red that contains an acid that reacts with bases and blue that contains a base that reacts with acids. The red strips will turn blue if the substance is alkaline, and the blue strips will turn red if they contact an acid. Litmus papers are generally used to provide a quick and easy test, but the cheapest litmus papers do not always provide accurate readings on the strength of the solution.
- Collect a sample of the water in a clean container. The water sample has to be deep enough to cover the test strip.
- Dip the test strip into your sample and give just a few seconds, exposure will suffice. The different indicator bars on the paper will begin changing color within a few moments.
- Compare the test strip with the color chart that has given with the paper. The color(s) on the chart has to be matched the color(s) of your test strip. The chart will correlate color patterns to pH levels.
Litmus paper only provides a quick check to see that your solution is acidic, neutral or basic. So if your solution is acidic, you still won’t be able to know if the pH is 2 or 6. For better accuracy, I would use either a pH meter or pH paper
Importance of pH test
Pure water should contain a pH of 7, though common tap water contains a pH between 6 and 5.5. Highly acidic water (water with a low pH) is more able to dissolve toxic chemicals, and these will contaminate the water and make it unsafe for human consumption.
So, it is considered as best to test pH on site. If you collect a water sample for study in a lab, carbon dioxide in the air will dissolve into the water. The dissolved carbon dioxide will react with the ions in the water to enhance acidity in basic or neutral solutions. To prevent carbon dioxide contamination, you have to test water within 2 hours of collection.
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Effects of pH value in the water
If you consume excessively acidic or alkaline water is harmful, it warns the Environmental Protection Agency (EPA). Drinking water must contain a pH value of 6.5-8.5 to fall within EPA standards, and they further note that even within the acceptable pH range, slightly high- or low-pH water can be unappealing for several reasons.
Water with high pH has a slippery feel, tastes a bit like baking soda, and may leave deposits on fixtures- declared by the EPA website. On the other hand, water with low pH may have a bitter or metallic taste and may contribute to fixture corrosion.
How Does Water Become Acidic or Alkaline?
The natural pH level of water is close to 7, that’s the neutral point of pH scale with better taste. It also safe and healthy for your body and the pipes of your house. Keep that in mind that acid rain, pesticide contamination, the type of minerals in rocks of the geological area, and metal leaching from pipes can affect the pH of the water and the level of pH can go up or down.
Determining by the level of pH, alkaline water contains a soda or bitter taste and can cause pipe corrosion. Water with 9 pH level of scale or above 9 may corrode copper, aluminum, zinc, iron, and brass. You will notice deposits on your dishes and will face difficulties in lathering soap from hard alkaline water.
The water is acidic, which can be determined if the pH of the water is less than 6.5. Acidic water contains a metallic or sour taste. This type of water may contain toxic levels of metals like manganese and iron. Pipes can be breakdown by running of acidic water into the pipe and leach metals from your pipes. You will also find bluish stains on your laundry and in your sink from this soft water.
How Do You Neutralize Water pH?
Sometimes it is needed to neutralize the water for working purposes. You can neutralize both acidic or base water. You can use acidic substances to neutralize base alkaline water, and also can use base alkaline substances to neutralize acidic water.
Here we will discuss how can you do the process at home:
★ A filter will be placed at the point where the water enters your home. Calcium carbonate is the carbonic salt of calcium. It is the substance we will use to neutralize alkaline water. A synthetic magnesium oxide substance can neutralize the acidic water.
★ You can install an injection system where the water enters your home. Soda ash can neutralize acidic water. You can inject that into the water. Acetic acid can neutralize high alkaline levels of water. It can be found in vinegar, citric acid or alum.
But injection systems need more maintenance than a filtering system.
★ A water distillation system is very effective and popular to neutralize the pH of water which is acidic. The distiller heats and properties and components of the acidic particles and form steam that is free from acid.
★ Electrolysis is effective for the water ionizer system. During the system running on, it will separate the alkaline and the acidic parts of water. You can use both parts separately. The alkaline part of the water can be used for drinking, on the other hand, the acidic water can be used for washing and cleaning.
But ionizers are quite costly than neutralizing filters and neutralizing solutions.
Water that has been determined with a high acidity level, must haven’t gone through proper filtration measures and still contains pollutants like pesticides and chemicals that pose you to health risks and make it unsafe to drink. This can also be the cause of outdated pipes and water systems that have corroded or are made of older materials as lead and copper. Water with a high acidity level that falls below a 7 on the pH scale will also likely carry an odor and not taste as clean as water that’s ready to drink. So, always should check the pH level of water and make sure to have safe and pure drinking water.
Frequently Asked Questions about PH Level
Why is the pH of drinking water important?
The pH level of water measures how acidic or basic it is,. Minerals in water don’t just add to its taste and healthfulness, but they have a huge effect on the water’s pH. This is important because the human body has a natural pH of 7.4.
What pH levels are dangerous?
The danger of more acidic water – when the pH is less than 6.5 – is that it can bring out metals from the well and from the pipes that bring you water. These metals include lead, manganese, copper, and iron, and they can be toxic in large amounts and harmful for the body.
Why is pH important in body?
pH balance of body also referred to as its acid-base balance, is the level of acids and bases in blood at which your body functions best. The human body is built as it can naturally maintain a healthy balance of acidity and alkalinity. The lungs and kidneys play a key role in this process.
What is the use of pH?
pH measurement is used in a wide variety of applications like agriculture, wastewater treatment, industrial processes, environmental monitoring, and in research and development.