Target TDS for Remineralized RO Water: The Numbers That Matter

A TDS meter gives you something concrete to verify, and the targets are specific enough to be useful.
Understanding reverse osmosis water mineral replacement in the Context of Remineralization
TDS stands for total dissolved solids.
A TDS meter does not tell you which minerals are present or in what ratio.
Raw RO output typically measures between 5 and 20 ppm.
Why 50 to 150 ppm
At the lower end, 50 ppm provides enough mineral content to noticeably improve taste and mouthfeel over straight RO output.
WHO guidelines on drinking water quality recommend a minimum of 10 mg/L calcium and 10 mg/L magnesium.
For drinking, 50 to 150 ppm covers the practical range for most households.
What to Do With Your Reading
For drops, increase the dose by 25 percent and retest.
For blending, increase the RO water proportion until the reading falls within range.
Adjust if the taste is noticeably heavy or if scale buildup on glassware suggests hardness is climbing.
How to Test Accurately
Dip the TDS meter into the sample rather than running it under the stream for a more stable reading.
For general drinking water verification, factory calibration is sufficient.
Target tds for remineralized ro water is 50 to 150 ppm for drinking, 100 to 150 ppm for coffee, and species-dependent for aquarium use.