Water chemistry adjustment question

[Grizwold]

Using BS v. 3--Adjusting water chemistry. Entered my Ward Labs report data. Designing a recipe with 12 gallons total water, the additions are split into mash and sparge. Want to heat the total water  all at once, use part for mash, reheat as necessary to use remainder as batch sparge. Do I combine the additions or must I do two separate additions?
Thank you!
edit: Is it even necessary to treat sparge water assuming there are no glaring deficiencies?

[Oginme]

Since you are heating all the water together, you can add the additions into your combined water as you heat it up.  I do mostly full volume mashes, but on occasions when I do sparge, I add all my water treatment salts to the mash and sparge with straight water.  That said, my water is very soft and does not impact the pH greatly during the sparge.

[Grizwold]

Thanks Oginme! BTW I am getting the Anvil 6.5 soon. I'll try not to be a nuisance but I see you have a lot of experience with using it.

[Oginme]

Don't worry about being a nuisance.  Being of help is one of the reasons I am here!