Was messing around and put together a wee excel sheet to work out what to put where if using DLS additions and Bru'n water spreadsheet.
Thanks to Dempsy for posting the makeup of DLS.
Any way, usual caveat, use at your own pearl. This a guide only. But may be handy to some. Also if you spot mistakes, issues, feel free to correct. I ain't precious.
Based on how much calcium you need, enter it in the cell provided ( worked out from entering your water details to brun water) And enter how much water you are going to use.
Then it will work out how much dls is needed, plus what other salts the dls will add, and break it in to what g/l to enter in brun Water salt additionsto reflect the additions. (so you can adjust for sodium or sulphates instead)
Did use a factsheet on dls available on craft beer (, Google dls factsheet) as reference, but using full volume salt additions (instead of brew length). Also in the excel sheet, worked out additions as per brupaks info, and as per brun Water's info, so you can use which ever you prefer (slight difference).
Anyway, as I say it may be of use. (possibly other such calculations out there, but didn't find any on a casual search)