Drowning in water calculations

When adding compounds to the brewing water, do you need to load up the sparge water as well?

Or just put the gypsum, epsoms, etc in the mash water and go with plain water to sparge?

Since some of the mineral content affects things other than the mash (like the bittering effect of the Burton water profile in English ales), I'd think you'd want to add minerals to the sparge water, too.

I do my additions to my total brew water, to include mash and sparge water.

Lots of good water info from John Palmer on How to Brew he also just updated his residual alkalinity spreadsheets which are pretty handy to have.

Thats what I use, Palmer's spreadsheets. Brewed this weekend and I just made the additions to the mash. Added the salts at the same time I added the grains. Palmer never really says when or where to make the additions but I interpreted that they are added just to the mash and not the sparge. The sparge water may need some lactic acid added to it. I also read that instead of lactic or phosphoric acid, you can add 1 tbsp DME per gallon of sparge water for the same effect.

Right. I've read Palmer and Noonan and various other articles and documents. And it's primarily the mash that's addressed. And calculations are usually given in regards to computing amounts based on mash water volume. The sparge and top off water is left ambiguous.

I would have thought the entire water supply should be identical, but the lack of information has me wondering if the additional chemicals are needed. And if not then why spend the money, etc.