If you are learning about your drinking water, you might have read about the term “TDS.” But what is TDS and what you do with this information?
What Is TDS In Water Testing?
TDS as it regards to water is an acronym for “total dissolved solids.” This refers to the salts, contaminants, small organic molecules (etc.) that are dissolved in water. The main inorganic components of TDS are calcium, magnesium, sodium, potassium, chloride, and sulfate. Organic molecules that contribute to TDS include carbon dioxide, dissolved organic matter, and simple sugars.
TDS is sometimes used as a measure of water quality simply because water shouldn’t have too many or too few TDS. Of course, what matters ultimately is what solids are dissolved in the water, which is why TDS is in many ways a limited and even a flawed metric of measuring water.
Even so, TDS is used to determine the suitability of water for drinking, irrigation, and industrial uses. High TDS levels can indicate pollution or the presence of minerals that can make water hard to treat.
How Is TDS Used?
TDS is a somewhat useful indicator of water purity and can be used to determine the suitability of water for drinking, irrigation, and industrial uses. TDS can also be used to monitor the performance of water treatment systems. For example, TDS can be used to measure the effectiveness of reverse osmosis systems if you measure the TDS in the water before and after the filter has done its job.
What Are The Benefits Of Measuring TDS?
TDS is a quick, cheap, and easy way to measure the overall water quality of a sample, particularly if you know what type of contaminants your water is prone to taking one. TDS doesn’t measure the types of contaminants or their impact on your health, but this test can let you know their total amount, which can be helpful in some applications.
What Are The Drawbacks Of TDS?
TDS does not provide information about specific contaminants that may be present in water. For this reason, TDS should not be used as the sole basis for water quality decisions. In addition, TDS measurements can be affected by factors such as temperature, pH, and the presence of other chemicals. As a result, TDS measurements should be interpreted in the context of other water quality parameters.
How Accurate Is TDS?
The accuracy of TDS measurements can be affected by factors such as temperature, pH, and the presence of other chemicals. As a result, TDS measurements should be interpreted in the context of other water quality measures and it rarely used on its own.
Is High TDS Bad? Is Low TDS Good?
There is no simple answer to this question. The suitability of water for a particular use depends on many factors, including the concentration of specific contaminants present in the water. In general, high TDS levels can indicate pollution or the presence of minerals that can make water hard to treat. Low TDS levels may be an indication of water that has been excessively treated and might not taste good or could be lacking in some minerals.
The World Health Organization (WHO) summarizes things nicely:
Water containing TDS concentrations below 1000 mg/litre is usually acceptable to consumers, although acceptability may vary according to circumstances. However, the presence of high levels of TDS in water may be objectionable to consumers owing to the resulting taste and to excessive scaling in water pipes, heaters, boilers, and household appliances…
The WHO says a TDS measurement of under 300 mg/liter is excellent ad 300-600 mg/liter is good, though, again, the types of dissolved solids are often more important than the amount of them.
How Is TDS Measured?
TDS can be measured using a handheld meter or a laboratory test. Handheld meters are typically used for field measurements, while laboratory tests are used for more accurate measurements.
What Units Are Used To Express TDS?
TDS is typically expressed in units of milligrams per liter (mg/L) or parts per million (ppm).