How to Check TDS Level & Ideal TDS for Drinking Water
Have you been hearing a lot about the TDS level in drinking water?
You must have.
Because that is what all the water purifier companies are talking about. That is one measure even consumers are talking about the most.
But, what exactly is this “TDS” and what is the ideal TDS for drinking water?
If you have no clue about what is the meaning of TDS in water, then you must read this post.
This post will provide you with all the details about
- What is the TDS level in water?
- How you can measure the TDS level?
- What is the ideal TDS level of drinking water?
TDS of Water Full Form
The full form of TDS in drinking water is “Total Dissolved Solids”.
What is TDS Level?
TDS level of water is the measure of all inorganic and organic substances that are dissolved in water.
The most common inorganic substances that are found in water are magnesium, calcium, and potassium.
To a certain degree, the presence of these minerals in the water is healthy, but when the level becomes too much, it is a cause for worry.
Most common constituents of TDS levels, like calcium, magnesium, etc., are generally harmless. But heavy metals like lead, mercury, arsenic, and fluoride can be really dangerous for your health.
Why Do You Need to Check TDS Level?
A study conducted by IIT Kharagpur revealed that almost 20% of India’s total land area has toxic levels of arsenic in its groundwater.
A significant number of Indians are drinking toxic water.
This is also evident from the data released by the Ministry of Jal Shakti in the reply to a question asked in Rajya Sabha on 1st August 2022. It was revealed that:
- Arsenic was found in around 209 districts in 25 states and UTs
- Uranium was found in parts of 152 districts across 18 states
- Lead was found in parts of 176 districts in 21 states.
- Iron was found in parts of 491 districts in 29 states and UTs
- Cadmium in parts of 29 districts in 11 states
- Chromium in parts of 62 districts in 16 states
Although TDS level does not tell you anything about the presence or absence of any of the contaminants that make up the TDS level.
But it gives you an initial idea of the overall quality of your drinking water.
And the best part is measuring the TDS level is very easy, as you’ll see below. So, there are no excuses for not knowing the TDS level of the water your family drinks.
A high TDS level (above 500 mg/l) indicates that the water quality is not good and you should not drink such water without purification.
Apart from the TDS level, there are around 50 other individual contaminants.
A thorough investigation of drinking water quality is only possible at a drinking water testing lab.
How to Check the TDS Level of Water at Home?
There are several methods for measuring the TDS level of water.
Below we have provided step-by-step tutorials on how to find the TDS level of water at home with and without using a TDS meter.
Method 1: Using Digital TDS Meter
The easiest way to find the TDS level of water at home is by using a digital TDS meter.
A digital TDS meter is an affordable, small, and easy-to-use device.
Use a digital TDS meter to check the performance of your RO water purifier, test the water quality, check for hardness, and ensure that you are drinking clean water.
Digital TDS meters are widely available in all the leading online stores in India and you can easily buy a quality Digital TDS Meter from Amazon.in for a few hundred rupees.
Here is how you can use a digital TDS meter to measure the TDS Level of water:
- Remove the protective cap.
- Turn the TDS meter on. You will find the ON/OFF switch is on the panel.
- Immerse the meter into the water up to the maximum immersion level (2 inches).
- Gently stir the meter to dislodge any air bubbles.
- Wait till the reading stabilizes (approximately, 10 seconds).
- Press the HOLD button and take it out of the water to view the reading.
- If the meter displays the ‘x10’ symbol, it means that you have to multiply the reading by 10.
- After use, shake off the excess water from your meter and replace the cap.
Watch this video on how to measure the TDS level in drinking water.
Precaution:
- Do not dip the meter beyond 2 inches because the meter is not watertight.
- Do not store the meter in places of high temperature or where direct sunlight comes.
Method 2: Using Filter Paper and a Scale
This conventional method was used before the invention of digital TDS meters.
We do not suggest using this method now as it requires a lot of time and effort. The final results are also not very highly reliable and the whole process is prone to error.
What are the things that you need?
- A sterilized beaker.
- A sample of water (tap water or rainwater) in the beaker.
- Filter paper.
- An evaporating dish.
- A stirring stick.
- A pipette that is large enough to collect a water sample of 50ml.
- A scale to measure.
Now, follow the instructions:
Step 1 – Weigh the evaporating dish in milligrams and make sure that the dish is empty, and free from any kind of particles. Note this measurement as “A” and come back to it after all the steps have been completed.
Step 2 – Take the stirring stick and vigorously stir the sample of water in the sterilized beaker. You need to agitate the liquid so that the particulate matter present in the beaker gets evenly distributed.
Step 3 – Take the pipette and collect 50ml of the stirred water. Please note that even while collecting the water, you have to continue stirring the liquid.
Step 4 – Extract water from the pipette and pass it on to the filter paper 3 times. There will be some sediment left behind in the filter paper.
Step 5 – If you see any particles in the filter paper, transfer them to the evaporating dish.
Step 6 – Wait for the filtrate (particles) to completely dry.
Step 7 – Once the filtrate on the evaporating dish is dry, weigh the evaporating dish again (with the filtrate) and call it “B”.
Step 8 – Measure the TDS level by subtracting B from A.
To check TDS level, use the formula: TDS = [(A-B)*1000]/ml
In this formula, A stands for the weight of the evaporating dish + filtrate, and B stands for the weight of the evaporating dish. Since 50ml was the quantity that you took in the pipette, the value of “ml” in this case will be 50. The final value of the dissolved solid is going to be measured in mg/L.
Precaution:
- Carefully weigh the evaporating dish and also, the weight of the evaporating dish with the filtrate.
- Wait for the filtrate or particles to completely dry before proceeding.
Most people often confuse the TDS level with water hardness. High TDS levels do not always mean that the water is hard. If you want to find out the hardness level of water then you should perform a water hardness test.
What is the Ideal TDS Level of Drinking Water?
World Health Organization (WHO) report on TDS in drinking water points out that reliable data on possible health effects associated with TDS in drinking water is not available.
No health-based guideline value is proposed for the ideal TDS of drinking water. Because TDS in water can be high because of many factors, in areas where the TDS content of the water supply is very high, the individual constituents should be identified.
The presence of dissolved solids in water may affect its taste. The palatability (acceptable taste) of drinking water has been rated by panels of tasters about its TDS level as follows:
| TDS Level (mg/l) | Rating |
|---|---|
| Less than 300 | Excellent |
| 300-600 | Good |
| 600-900 | Fair |
| 900-1200 | Poor |
| Above 1200 | Unacceptable |
What is the maximum TDS level advised by the Indian Authorities?
The Bureau of Indian Standards (BIS) has set the acceptable limit of TDS in drinking water at 500 mg/L.
However, the standard also mentions that in case no alternative source of drinking water is available, then this acceptable limit can be relaxed to 2,000 mg/L.
The BIS water quality standards also mention that if the drinking water TDS is higher than 500 mg/L then this may result in a decrease in palatability (acceptable taste) and may cause gastrointestinal irritation.
Whether you get your water from a borewell, water tanker, or municipal tap, you must make sure that it meets the BIS water quality standards. If your drinking water’s TDS level exceeds 500 mg/L, we suggest that you do not drink that water.
Minimum TDS Level for Drinking Water
It is important to note that some of the dissolved minerals in water are useful for human health and therefore very low or zero TDS is also not recommended.
Reducing the TDS level to a very low value also affects the pH level of the water, which BIS specifies should be in the range of 6.5-8.5. Water with very low TDS will taste dull.
There is no official minimum TDS level for drinking water, but a TDS of at least 50-150 ppm is the accepted minimum level.
| TDS Level (mg/l) | Reasons for Acceptability/Non-acceptance |
|---|---|
| Less than 50 | Safe but not ideal. You may find the water tasteless as water with such a low TDS level does not contain the essential minerals. |
| 50-150 | Acceptable. However, a TDS level in the range of 80-150 is considered ideal. If you are using an RO water purifier then make sure the TDS level of purified water is not below 80 mg/L. |
| 150-250 | Not acceptable. Use an RO water purifier with a TDS controller or mineralizer. |
| 250-350 | Acceptable. Most urban Indian homes have access to water in this TDS range. |
| 350-500 | Acceptable. As per the BIS guidelines, a TDS level below 500 mg/L is acceptable. |
| 500-900 | Not acceptable. Use an RO water purifier with a TDS controller or mineralizer. |
| 900-1200 | Not acceptable. Use an RO water purifier with a TDS controller or mineralizer. |
| 1200-2000 | Not acceptable and not fit for drinking. Choose a RO water purifier that can purify water with up to 2000 mg/L. |
| Above 2000 | Do not drink. Most home water purifiers can’t purify water with a TDS level over 2000 mg/L. |
Check out the following link if you would like to learn more about how Total Dissolved Solids come in water and what is the effect of low or high TDS on your health.
TDS Level in Drinking Water – FAQs
Always remember that a high TDS does not necessarily mean that the water is unsafe for consumption. Sometimes it may be a bit odd in terms of taste, color, or smell. Ideally, the TDS for drinking water should be below 300 mg/liter and the maximum limit that is considered safe is 500 mg/liter.
If you are eager to find out how good or bad your drinking water is, then you should get your drinking water tested.
Water purifiers that come with reverse osmosis (RO) technology are a great solution to reduce high TDS levels in the water. These purifiers are built with cutting-edge technology to ensure that the TDS levels in water are reduced and that the water is safe for drinking. If you are planning to buy one, then you can check the latest range of RO water purifiers.
Click to read: Can Water Softeners Lower the TDS Level of Water?
With the help of a TDS meter, you can even check the longevity and functionality of the RO membrane and replace it, if need be.
Share this information with your friends and family to equip them with the knowledge needed for checking the TDS level in drinking water. If you know of any other way to measure TDS levels, please feel free to comment.
This article is very informative and helpful for those who want to check the TDS level of their drinking water. Thank you for sharing this information.
I have an old Aquaguard filter. My inlet water TDS is 232ppm and even after going through the aquaguard filter the TDS level is 232ppm. Do you think I need to buy a new filter? The PPM is below 300 which means ideally the water is good.
It is more than a useful message. Thank you.
What kind of purifier are you using at present and what is the source of water? If there is no difference in the TDS level of the input and output water then you are certainly not using an RO purifier. Or your RO membrane is damaged.
My bore well water TDS level is 180. Is it safe for drinking? And there is a little bit of smell in the water too. Can I drink that water or not?
The TDS level is fine. The water is safe to drink as long as it does not contain any harmful heavy metals like lead, arsenic, etc. There can be several reasons for the smell. Are you drawing the water directly from the ground or is it supplied by a third party?
Hi Experts,
We are using Pureit Mineral Copper+ RO+UV+MF water purifier.
Yesterday the GKK2 kit was replaced.
The output water TDS is showing 35 PPM whereas the inlet TDS is 375.
The technician informed me that TDS level can’t be adjusted in this purifier and its always output is 10% of input TDS.
There is TDS modulator which is connected after RO and before UV, its newly replaced. But if that works it should increase the TDS level more than 10%?
As per the WHO standard, drinking water below 50 PPM is unacceptable as it lacks required minerals and is tasteless.
Unfortunately the technician doesn’t have any knowledge in this.
Can you please comment?
Thanks,
Venkat
Very good demonstration 😄
This purifier does not have any TDS modulator, therefore TDS can’t be adjusted.
As per my water technician, the Aquaguard RO water purifier is showing 210 after testing with the TDS meter. Is it good for health or do we need to change the filter? Thanks in advance.
That’s a little higher than the usual TDS level of the RO purified water. What is the source of water and what is the TDS level of the incoming water?
Below 15 Tds is advisable for safe consumption
My borewell water TDS level is 650 ppm so I bought Aquatec water purifier. Now the TDS level of purified water is 20 ppm. Is this good? Please suggest me. Thanks.
Is 555 TDS level good for drinking
My RO gives the water which TDS level is 98. Is it suitable for drinking?
Yes, it’s fine.
As per BIS standards, you should ideally drink water that has a TDS level below 500 ppm. What is more important than the TDS level is the constituents of TDS. If your water contains harmful heavy metals like lead, arsenic, and mercury, then water with a TDS level of even 100 is unsafe. And if it doesn’t contain any such harmful impurities then water with a TDS level of 500 is also safe.
There is no reason to worry, as long as you are able to meet the dietary requirements, for essential minerals like Calcium and Magnesium, with what you eat. Do you have a TDS controller in your water purifier? If yes, then we recommend adjusting the TDS controller to get purified water with TDS of at least 50-80 PPM.
Thank you very much for the information. TDS level is 5 in RO water and tap water TDS level is 95.
Now we are planning to alter the RO.
How do I know if the TDS meter is working perfectly? Is there a sure-shot way to know or verify it’s measuring accuracy?
I live in Gurgaon and one of the TDS meters I bought is showing tap water value as 94ppm whereas other people in the locality say that it should be much higher. Can I take some standard bottled/mineral water of some brand that has printed TDS to verify the TDS meter accuracy with it?
Sir have you ever used p&g purifier, they said that p&g purifier can filter water and save you from dirt, parasites, pesticides & other contaminants and kills bacteria & viruses. Sir if you have used this before then tell it’s useful or not.
No, we have never heard of this brand.
My RO is showing 9 & tap water is showing 123 which is better for drinking?
TDS level is 18. Is this safe?
Yes, it is safe. There can be a debate on whether low TDS water is ideal or not but low TDS water does not pose any safety risk.
My RO is showing 4 TDS value is it suitable for drinking & cooking, please suggest.
TDS value of 4 is extremely low. That means the water you are drinking is devoid of all essential natural minerals. What is the source of water?
My can water shows 34 and filtered with Pureit shows 21. Is it safe to drink? Checked With TDS digital meter.
Yes, it is safe to drink.
TDS level of 9 ppm is very low and is not advised for drinking. Since you are having tap water supply and the TDS level of tap water is just 123 ppm, we suggest using a UV+UF water purifier instead of an RO water purifier.