TDS meter and Coldstream FTO+ filters

It is of primary importance to note that a Pure water filter does not work as a reverse osmosis system which removes all the minerals from the treated water. The main purpose of a Pure water filter is not to remove all dissolved solids from the water. The Coldstream FTO+ filters are designed to leave undisturbed the natural minerals present in the water.

A TDS meter does not measure the level of contaminants and pollutants in the water and therefore does not provide a direct indication of water purity. Beneficial minerals such as potassium, magnesium and calcium can lead to high PPM readings on a TDS meter. Additionally the water may contain heavy metals such as lead, as well as other contaminants such as pesticides, pharmaceuticals or bacteria, which the TDS meter cannot detect.

A TDS meter measures the total amount of dissolved solids in the water, in other words the amount of mineral salts in solution. When water falls to the ground in the form of rain it dissolves the minerals present in the rocks and soil through which it passes, in the process mineralising the water. This natural process helps to give the water a pleasant taste by slightly increasing its pH level. The most common minerals found in water are calcium, magnesium, and sodium.

A TDS level of less than 200 mg/L (or ppm) is considered good, and 100 mg/L is even rated excellent. When TDS levels drop below these values (as minerals are removed), the pH of the water drops making it more acidic or corrosive which significantly impairs it’s taste. TDS levels above 400 mg/L are considered to be non-potable.

It should be remembered that a Pure water filter is not a water softener and its main purpose is not to remove all dissolved solids from the water. Mineralised water is necessary for human health so their presence in the filtered water is beneficial. An effective water purification system should filter out substances harmful to the body while preserving essential minerals.

A TDS meter will reveal little change between the water before and after filtration with the Coldstream FTO+ filters. This is normal as the measurement of total dissolved solids (TDS) includes various charged ions such as minerals or salts dissolved in a given volume of water. This is expressed in mg per unit volume (mg /L) or parts per million (ppm).

The measurement of TDS, which represents the total amount of charged ions including minerals or salts dissolved in a given volume of water is not an absolute indicator of water purity or the quality of the water purification system.

When customers use a TDS meter they often notice that the reading before and after filtration usually remains unchanged. This is explained by the fact that the Coldstream FTO+ filters do not remove the beneficial minerals from the water. The Coldstream FTO+ filters primarily remove unwanted heavy metals such as lead and mercury, as well as sedimentary minerals such as iron oxide.
Therefore, the TDS reading does not vary significantly unless the water contains a significant amount of heavy metals or sedimentary minerals.

It is crucial to understand that the TDS meter does not measure the presence of biological and chemical contaminants. It is therefore unwise to rely solely on this measure to assess the quality of water. Water with a low TDS content can contain harmful bacteria, while water with a high TDS content can be perfectly safe, such as pure, unpolluted seawater.

A slight increase in TDS levels may occur during the initial use of the filters and is a normal phenomenon.  These TDS measurement variations are temporary and will normalize with continued use of the system.