Faq categories
- Ultimate Star Filter® [20]
- General questions about water filtration [3]
- Installation, servicing and maintenance of Star Water Filter® water filters [4]
- Troubleshooting Star Water Filter® water filters [5]
- Receipt of your Star Water Filter® water filter [4]
- Star Water Filter® orders and delivery [5]
- Use, hygiene and maintenance [1]
Can I use a TDS reader to check my filtered water?
This is a fairly recurrent question, and many people tell us how surprised they are when they read their filtered water readings taken with a TDS (or conductivity) meter.
Let's start by being very clear : a TDS reader cannot be used to check the quality of water, and even less to tell whether or not there are pollutants in the water. That's absolutely not what this device is for. It's like using a screwdriver to drive in a nail or a hammer to fix a screw...
What is a TDS reader used for?
TDS stands for Total Dissolved Solids and is used to measure solids dissolved in water in ionic form. These can be salts, minerals or metals. This device actually measures the conductivity of the water. The more solids dissolved in water, the more electrically conductive it is.
The readers, or TDS meters, therefore indicate a measurement that corresponds to the conductivity of the water, and this measurement is expressed in microsiemens or, more generally, in PPM (Parts Per Million). This unit corresponds to the number of solid particles per million particles of water. In other words, a value of 50 ppm means that in one million particles of water, there are 50 dissolved ions.
Can the value measured by a TDS meter indicate water quality?
Assuming that water with a value of 0 ppm is pure and free from pollutants is not true. The TDS meter only measures the number of ions dissolved in the water. However, most pollutants, whether pesticides, substances with endocrine effects or drug residues, are generally not ions. What we can say in this case is that the water is free of mineral salts, but it may be highly charged with various pollutants.
On the other hand, water with a high value in no way means that it is polluted. It just means that it contains a significant number of mineral salts or metals.
The value indicated by a TDS reader is therefore absolutely no indication of whether or not the water is polluted. Do not use this device for that purpose. The only way to find out is to have it analysed in a specialised laboratory, where samples are taken very precisely and according to a specific protocol.