pH Level in Drinking Water, Acceptable Levels | Explained!

One of the first wonders or magic of science is the changing of the colour of the litmus paper. All of us must have marvelled at how the blue litmus paper turns red in an acidic solution, and the red paper becomes blue when you dip it into an alkaline solution.

If my memory serves me right, I have also done these tricks like cutting a lemon with a knife dipped into a litmus solution. Those were our first experiences with the concept of pH.

What is pH?

In elementary terms, pH is the indicator for acidity and alkalinity. Any solution having pH value less than 7 is acidic, and more than 7 is alkaline. Pure water, considered to be the most neutral of all liquids has a pH value of 7.

Now, the colas you drink regularly have a pH value of around 2.5. It entails that they are extremely acidic. It also explains why one should not drink too much of the carbonated drinks. Similarly, apple juice has a pH value of 3. Orange juice 3.5, milk 6.2, and so on. All these liquids are acidic.

Now, coming to the alkaline solutions, you have baking soda has a pH value of 8.5, soapy water 10, and bleach 12.

What does pH mean for water?

We have seen earlier that pure water has a pH value of 7. Now, pure water is a tasteless, odourless, and colourless liquid. You need to add some salts or minerals to make the water palatable.

This addition of salts or minerals alters the pH value of water. The BIS has stipulated that water in the pH range of 6.5 to 8.5 is acceptable. The pH value of groundwater is between 6 and 8.5.

Effect of pH value on the taste of the water

Consuming water outside the BIS range is harmful to health. Let us see what can happen if you drink or use water outside this palatable range.

Acidic water

Water with pH level below 7 is acidic. If you consume water having pH levels below 6.5, you will find that it has a bitter taste. Acids have the property of corroding metals. If the input water source in your house is acidic, it is not safe because it collects metal impurities on its way towards your home.

Hence, you need to increase the pH levels of this water by removing the metal impurities. The RO water purifying systems are best equipped for dealing with such water.

Alkaline water

Similarly, water with a pH level greater than 8.5 is also not acceptable according to BIS. This water is extremely hard in nature.

One of the most significant effects of consuming alkaline water having pH value greater than 8.5 is that it causes scaling on the utensils and the heating coils of the water heaters. It does not have a pleasant taste either.

The municipalities all over the country use chlorine to neutralize the effects of the alkaline nature of the water. The more the hardness of the water, the more chlorine you have to use. It, in turn, affects your health.

Therefore, you use RO water purifiers and Ion Exchange water purifiers to neutralise the alkaline water.

You can also use water softeners to soften the water, especially if the water does not contain high levels of TDS. It is a better way of neutralising the water instead of using the RO water purifier.

Is drinking rainwater good for health?

It depends on when and how you drink it. It can surprise you that rainwater can be extremely acidic. The rainwater dissolves the Carbon dioxide, sulphates, and nitrates present in the air on its way down towards you.

If you measure the pH value of rainwater, especially in areas having high industrial and vehicular pollution, you will find the pH value to be somewhere between 4 and 5.5.

However, you can harvest rainwater and collect it in a storage tank. The rainwater harvesting process increases the pH value of the water and brings it between the palatable ranges. However, it is better to use a high-quality RO water purifier at home to purify the rainwater before consuming it.

Does altering the pH value of water make it suitable for drinking?

The pH value is not the only factor that determines the suitability of drinking water. Remember, our stomach secretes hydrochloric acid (pH value of approximately 1 to 3.5) Our body is capable of digesting acidic substances.

Does it not digest the carbonated drinks we have? All of us have coffee every day. Coffee has a pH value of 5.5. Similarly, we have vinegar with a pH value of 2.8 in our food.

However, as far as the palatability quotient is concerned, altering the pH value does make a difference in the taste of the water. A high-quality RO water purifier can help provide water in the range of pH value 7. The TDS controllers or the Mineralisers replenish some of the essential salts and minerals thereby increasing the pH value to somewhere between 7.5 and 8.5.

What are the effects of consuming acidic water?

Acidic water can corrode the pipes and metals. Therefore, acidic water contains heavy metal impurities that can adversely affect your health in many ways. These metal deposits accumulate inside our bodies and cause great harm.

Effect of alkaline water

You can also refer to alkaline water as hard water. Hard water, as such, does not affect our body. However, the water does not taste good. It can make your coffee bitter. The hard water can leave salt deposits on the vessels and bathroom fittings. The lathering of soaps becomes difficult. It can also result in the formation of insoluble precipitates on your clothing.

How do you test the pH level of water?

You get pH level testers on the market. These are simple digital equipment that can give you the pH level of the water within no time.

Type of WaterpH Level
Tap WaterIt varies from place to place. Usually, it should be around 7.5
Distilled RO water5 to 7
Bottled water that you get off the departmental store shelf6.5 to 7.5
Bottled water labelled as Alkaline8 to 9
Ocean waterAbout 8
Rainwater5 to 5.5


The key takeaway from this discussion is that one should consume water within the BIS acceptable range of 6.5 to 8.5. Use best water purifiers or Ion exchange appliances to alter the pH value of water to make it palatable. However, our body can maintain the pH equilibrium on its own. The water consumption does not affect it in any way.

Sources: WHO, Healthline

Chaithanya Vanjari
Chaithanya Vanjari
I'm Chaithanya Vanjari, the Creator and Editor-in-Chief at KitchenArena. With a decade of experience in evaluating large appliances like air conditioners, washing machines, refrigerators, and various small home devices, I possess the technical expertise needed to thoroughly review and understand the operational complexities of these appliances.


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