Amount dry acid or sodium bisulphate needed for varying hardness values [closed]








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My question is regarding the use of sodium bisulphate to lower the hardness of water. I am attempting to come up with a label to let consumers know how much product (dry acid or sodium bisulphate) is needed for varying hardness values. 


Using the equation $$\ce{CaCO3 + 2NaHSO4 -> Na2SO4 + CaSO4 + CO2 + H2O}$$I have found the following ratios:


$\pu{120 mg/L}$ $\ce{CaCO3}$ requires $\pu{0.288g}$ $\ce{NaHSO4}$,
$\pu{180 mg/L}$ $\ce{ CaCO3 }$ requires $\pu{0.432g}$ $\ce{NaHSO4}$,
etc.


**My question**: How much calcium will react with bisulfate? And how can I use this information to determine the change in hardness? Will starting pH of the water affect the calculation?


