Using a TDS Meter on Berkey Water
Why Doesn't a TDS Meter Work on Berkey Water?
Berkey water filter systems do not remove beneficial, ionic minerals (which is a good thing in most cases) and TDS meters read those minerals as total dissolved solids, which makes the reading show high numbers.
What is a Total Dissolved Solid?
A Total Dissolved Solid, also known as TDS, are the total amount of mobile charged ions in a give volume of water. The unit of measurement is milligram per unit volume (mg/L), also called parts per million (ppm). TDS meters measure dissolved minerals, salts, and metals. Both beneficial minerals (like calcium, potassium, etc.) and harmful sedimentary minerals (like aluminum, chromium and lead) are considered total dissolved solids.
TDS Meters and Water Quality
A TDS meter cannot identify between; healthy ionic minerals, harmful sedimentary minerals, and heavy metals. In other words, TDS is not a good way to measure the "cleanliness" of water because beneficial minerals are also considered total dissolved solids.
A TDS reading of zero would indicate the absence of all TDS, including healthy beneficial minerals, bad minerals, and heavy metals, this type of water is also called “dead water”.
It is our belief at Berkey Filters, that a water filter system should filter out things that are harmful to your body, but leave in the helpful things such as beneficial minerals. The Black Berkey elements, utilized in all our Berkey Systems, are designed, to do exactly that! The Berkey Black filter’s proprietary design allows healthful beneficial minerals (like calcium, potassium, etc.) to remain in your water and remove or reduce; chemicals, harmful sedimentary minerals, heavy metals and many other contaminants (200+ in total) see our independent test results!
When a TDS meter is used on Berkey Water, the reading both before and after the water has gone through the system is about the same. This is because the Berkey filters leave beneficial minerals (a TDS) in your water. This will be the case unless you have a significant amount of heavy metals or sedimentary minerals in your pre-filtered water.
Testing Berkey Water
Rather than using a TDS meter on your Berkey Water, we recommend running the Red Dye test. This is a simple test you run on your Black Filters to visibly see if the Black Filters are removing the chemically colored red food coloring. Please note only McCormick’s Red dye should be used as it is the only purely chemically composed red food coloring. Do not use gel coloring.
Important side note: When using a Berkey system for the first time, it is common for a TDS meter to initially show a higher reading, due to the manufacturer’s process dust and carbon that are compressed in the media of the filter element. After running four to five batches of water through your Berkey system, you should notice a this higher reading is reduced.