[delta66]

Το μαλακο νερο δεν στερειται μονο ασβεστιου.
Εκανες καποια μετρηση αναλυτικη και βρηκες οτι λειπει μονο ασβεστιο απο το νερο σου?

Water softening is the reduction of the concentration of calcium, magnesium, and other ions in hard water
http://en.wikipedia.org/wiki/Soft_water

Hardness can be quantified by instrumental analysis. The total water hardness, including both Ca2+ and Mg2+ ions, is reported in parts per million (ppm) or weight/volume (mg/L) of calcium carbonate (CaCO3) in the water. Although water hardness usually measures only the total concentrations of calcium and magnesium (the two most prevalent divalent metal ions), iron, aluminium, and manganese can also be present at elevated levels in some locations. The presence of iron characteristically confers a brownish (rust-like) colour to the calcification, instead of white (the color of most of the other compounds).
http://en.wikipedia.org/wiki/Water_hardness