Originally Posted by bobbrews
BTW -In addition to adding additional calcium without other unnecessary ingredients, and boosting alkalinity (if that is your goal), lime softening can also help to reduce hardness and adjust/maintain pH.
You seem to think that there is only one use for lime, across the board, for all homebrewers, in each and every circumstance.
I never said that there is only one use for lime. In fact I believe I also mentioned that you could use it for lime softening. All I was saying is that normally pickling lime is used to raise alkalinity (and thus mash pH). Besides, if he does use pickling lime to soften his water, and he does it properly, then he's going to lose any of the calcium that the lime added to the water. He'll need to add extra gypsum or calcium chloride to the water if he doesn't want to end up simply increasing his alkalinity (by adding too much lime).
EDIT: The last part assumes he wants to have at least 40-50 ppm calcium instead of 20ppm.