Assuming distilled water for the sake of a baseline, adding how many grams of calcium chloride per liter would equal, say, 55ppm (the middle of the range you gave)?
I found this unit converter that converts ppm to g/liter:
https://www.unitconverters.net/concentration-solution/part-million-ppm-to-gram-liter.htm
So, according to it, 55ppm = 0.054937245 g/liter.
But that doesn't really answer the question, because it doesn't account for the weight of the chloride that's the other half of the calcium chloride. Does one just compare the molecular weight of chloride to calcium and then scale up the 0.054937245 g/liter proportionately to get the g/liter of calcium chloride?
Or is there an easier way to compute the g/liter of calcium chloride that would need to be added?
Regardless, it would seem the weight of the calcium chloride addition is going to be pretty small.