# Do TDS meters measure HCO₃⁻/CO₃²⁻?

I am trying to add $$\pu{2 g}$$ of $$\ce{KHCO3}$$ to $$\pu{20 L}$$ of RO water $$(\mathrm{pH} = 5.2)$$ which theoretically it will add

$$\begin{array}{lr} \hline \ce{K+} &\pu{10.32 ppm} \\ \ce{HCO3-} &\pu{16.1 ppm} \\ \hline \end{array}$$

Will my TDS measure only the $$\ce{K+}~(\pu{10-11 ppm})$$ or it counts also $$\ce{HCO3-}~(\pu{26-27 ppm})$$ (or even $$\ce{CO3^2-})?$$

• In my understanding, TDS meter estimation is based on conductivity measurement, so it takes into account all ions. – Poutnik May 20 at 3:56