Have you ever felt that the water you are drinking has a bland or salty, or bitter taste? Do you know why sometimes the water tastes so unpalatable? Let me answer this for you. It is due to the concentration of Total Dissolved Solids or TDS present in that water. TDS measures the amount of dissolved combined content of all inorganic and organic particles present in a liquid, mostly water, in ionized, molecular, or colloidal sol suspended form.
Nevertheless, we often tend to misunderstand high TDS levels with bad water quality or contaminated water. Whereas the Total Dissolved Solids reading gives an account of the qualitative measure of the number of dissolved ions and not about the nature of the water. The TDS tests do not even provide an insight into specific water quality issues like Elevated Hardness, Salty Taste, or Corrosiveness. Hence, it can be said that the TDS test is just an indicator to measure the general quality of water. Further, this article will give you an overview of TDS, TDS meters, how does a TDS meter work and operate, and why we should check TDS levels in detail.
What Is TDS?
Total Dissolved Solids or TDS, as it is popularly recognized, can be determined as the total concentration of the dissolved solids present in water. In simple words, it can be said that TDS is the sum of the anions and cations present in the water. Since water is a universal solvent, it absorbs and dissolves impurities quickly.
Total Dissolved Solids comprise inorganic salts (calcium, magnesium, chlorides, sulfates, bicarbonates, etc.) as well as a small amount of organic matter. In drinking water, TDS may arise from different places such as natural sources, sewage, urban run-offs, industrial wastewater, chemicals utilized in the water treatment process, chemical fertilizers used in the garden, plumbing, etc.
High TDS of water is generally not considered a health hazard. However, it tends to alter the salinity and taste of water, making it bitter, salty, or brackish in taste.
1. Why Should you Measure Total Dissolved Solids Levels?
We know that the quality of water is pure in nature. Taste, odor, and color are absent in them. If you want to check the overall quality of the water, the drinking water TDS levelmust be determined. If the TDSlevel in water isvery high, then it may probably affect the taste of the drinking water.
Water has a bitter, salty, solid, or sometimes a sulfuric taste and it greatly depends on the type of organic materials present. Water is not at all drinkable if the TDS of water is higher. If you conduct routine testing for TDS, then it reveals whether the working of the filtration system is going well or not.
Water that comprises of increased levels of dissolved calcium and magnesium results in high TDS levels and hard water. When the hard water gets collected in the pipes it may forms scale and build-up. So, there needs an expensive replacement for pipes. This is the reason one needs to have a good quality water purifier at home.
2. Acceptable Drinking Water TDS Chart
Check the following chart of TDS present in drinking water according to the taste of water.
|TDS Levels (in MG/L)||Ratings|
|Level Less than 300||Excellent|
|Level between 300-600||Good|
|Level between 600-900||Fair|
|Level between 900-1200||Poor|
|Level Above 1200||Unacceptable|
3. Palatability Levels of TDS
|TDS Levels mg/litre||Palatability Quotient|
|Any level of TDS less than 300||Is Excellent for Drinking|
|TDS Levels More than 300 and up to 500||Acceptable Levels|
|TDS Levels between 500 to 900||You can eliminate the excess TDS in these levels by using water purifiers, so it is a fair level|
|TDS Levels between 900 to 1200||A very High-quality water purifiers can reduce the TDS levels in this range too. But, water having a TDS level in this range constitutes poor palatability|
|TDS Levels Above 1200||It is completely an unacceptable range for everyone|
What Is TDS Meter?
The most efficient way for measuring the TDS of a water sample is by evaporating the liquid and weighing the solid particles that remain after the evaporation. However, this might not always be feasible. Hence, a TDS meter is utilized to determine the total amount of dissolved solids present in water. A TDS meter or a Total Dissolved Solids Meter is a small-sized handy device that indicates TDS in a solution, mainly water.
A TDS meter estimates the TDS in a sample by measuring the conductivity of the solution. The idea behind measuring the conductivity comes from the fact that generally, the dissolved solids like salts and minerals present in water increase the conductivity of a solution. Along with normal drinking water, a TDS is also utilized for measuring the amount of total dissolved solids in borewell water, pools, aquariums, spas, hydroponics, etc. If you feel you need to use a TDS Meter, you can look at our article, “Best TDS Meter In India” to choose an accurate and trustworthy TDS Meter.
I. How to Use TDS Meter?
A TDS meter is a very simple and reliable device that we can use to determine the TDS of water. The reading of TDS meters comes in parts per million (ppm). The principle on which a TDS meter works depends on the measurement of the electrical charge of the dissolved solids. The device emits a small electrical current that passes through the water to be tested. Then this electrical conductivity is captured by the meter and converted into a TDS number. Few meters can provide both the actual EC (electrical conductivity) reading and the TDS value. You can operate a TDS meter by following the given steps:
Step 1. Remove the cover from the bottom of the tester
Step 2. Turn on the unit by pressing the On/Off button. The display should read 000.
Step 3. Insert the tip of the tester into the water sample to be tested
Note: Do not submerge the tip more than half an inch to prevent damaging the TDS meter.
Step 4. Read the numbers on display expressed in PPM. This number shall determine the TDS value of the sample.
Step 5. You can press the Hold button for locking the number on the display so it won’t go away.
II. An Overview Of TDS Levels
WHO has stated that the acceptable range for TDS level in a water sample is around 300 ppm. TDS level of water within 300 ppm is suitable for human consumption. Although a TDS level higher than 300 ppm is certainly not hazardous to health. Yet, the water may not be palatable enough for us to drink it due to the presence of a high concentration of minerals like sodium, potassium, and other salts in it.
However, TDS levels beyond 1000 ppm are considered unfit for drinking purposes. In fact, TDS levels that are more than 1200 ppm are declared unacceptable by WHO. This extreme spike in TDS levels might alter the water’s color, odor, and taste. Moreover, water with high TDS concentrations causes excessive scaling in water pipes, heaters, boilers, and household appliances.
What Does A TDS Meter Reading Imply?
There is no certainty that the TDS level will indicate whether or not the water contains contaminants. A higher TDS meter reading doesn’t necessarily mean the water is unsafe. Nevertheless, it could indicate that further testing is required. High TDS meter readings are usually the result of the presence of high mineral content, making the water hard.
Hard water can be turned into soft water by using a few methods that are mentioned in our article of “How To Make Hard Water Soft“. Low TDS meter readings might be an indicator of corrosion. These lower levels can affect the pH of the water, making it more acidic and corrosive. The TDS levels vary based on the area or country in which you live.
A high TDS level simply indicates that there could be particles that might affect the taste and smell of the water. A water filter may help in correcting the high TDS levels. It should be kept in mind that high TDS concentrations don’t mean that the water is unsafe or unfit to drink. However, although a Total Dissolved Solids meter is a simple way to check and monitor the TDS levels regularly, it is not a method to rely upon for judging the water quality after all.
How to Check TDS in Water Using Filter Paper And Scale
Although, this method is conventional, people often use it easily in their home to measure the TDS levels in your drinking water.
What are the things that you require?
- Sample of water (can be tap water or rainwater) in the beaker
- One sterilized beaker
- A Filter paper
- A stirring stick
- An evaporating dish
- A pipette which is large enough to collect a water sample of 50ml
- Scale to measure
Now, follow the instructions:
Step 1 – Take and Weigh the evaporating dish in milligrams and ensure that the dish is totally empty, free from any kind of particles. Note this measurement as “A” and we will get back to it at the end
Step 2 – Take the stirring stick and stir the sample of water in the sterilized beaker. You need to agitate the liquid. The particulate matter existing in the matter gets equally distributed.
Step 3 – Take the pipette and take out 50ml of the stirred water. Note that even while collecting this water, you must resume stirring the liquid continuously.
Step 4 – Extract the water from the pipette and pass it on to the filter paper 3 times. The sediment remains in the filter paper.
Step 5 – If you find any particles in the filter paper, then transfer them to the evaporating dish.
Step 6 – Now, wait for the filtrate (particles) to dry completely.
Step 7 – Once the filtrate on the evaporating dish is dry, weight the evaporating dish again (with the filtrate) and call it “B”
Step 8 – Measure the TDS level by subtracting B from A
Elevated TDS levels do not indicate that the water is a health hazard. But it might direct that the water has aesthetic issues or create nuisance problems related to taste, staining, or precipitation. Higher TDS levels may suggest that total dissolved solids may indicate the presence of heavy metals that prove to be toxic to humans. A TDS meter may come in handy to keep a check on the TDS levels regularly. This is considered the most ideal and practical approach to find out about water TDS levels.