TDS Meter FAQs

I used a TDS meter and the results were positive. Is my water filter faulty?

No. A TDS meter is a broad test used to determine levels of Total Dissolved Solids (TDS) in a liquid, whether good or bad. This would include the content of all inorganic and organic substances in molecular, ionized, or micro-granular (colloidal sol) suspended form. Common TDS substances include calcium, phosphates, nitrates, sodium, potassium, and chloride. Water that is completely void of any TDS is often described as having a flat, unpleasant taste, and would be lacking in important, healthy minerals your body needs. To know for sure whether or not your water filter is functioning correctly, you would need a test that focuses specifically on the contaminants the filter claims to remove, such as chlorine or lead. A TDS meter has too broad of a test range to give an accurate reading for the functionality of a water filter.

I used a TDS meter and the results were higher after the water was filtered. Is this normal?

Certain types of filter media can result in a higher TDS reading after the water has been filtered. For example, with a carbon filter, the granulated activated carbon (GAC) coconut shell media tends to flake off, particularly at first use. The tiny, harmless carbon particles would then result in a higher TDS reading. After being properly flushed, the amount of carbon residue will decrease, but carbon filters always tend to result in higher TDS readings. In general, a TDS meter is not a good indicator of how well your water filter is working.

Back to Water Filters FAQs