"David L. Martel" wrote in message
...
Clare,


If tou start with very hard water, the softened water will contain no
more than 13mg of sodium in a large glass of water - still very low
sodium. (assuming your softener is working reasonably well)

My water is quite hard, 35 Gr/gal. That's about 2270 mg. of Ca in a
gallon. That's about 0.11 moles of Ca. So my water softener will put out
0.22 moles of Na in exchange for the Ca. That's about 2430 mg of Na in a
gallon. Assuming that your large glass of water is a half pint that's
about 150 mg.
Where are you getting your 13 mg. figure? Check my math, did I make a
mistake? Why can't the water be harder than you say?

Dave M.

Calcium bicarbonate is not very soluble in water so even a saturated
solution does not amount to much.
Hence when softened, there is not much sodium bicarbonate.
Whether there is enough to effect you health, there is debate about.

But hard water is good for you to drink and tastes better, no doubt.