Depending on what salt you use for your make up will determine what you'll need to add if anything. I never added anything to my make up water but Instant Ocean. My alk and calcium was supplemented seperately using B-Ionic 2 part daily.
I -do- supplement with a kalk drip (lime water), about 1g per day over a 24 hour period to keep my alk/ph in line. I use Oceanic salt which keeps calcium high, but alk runs real low without the supplemental drip.
It's the OceanPure Pro Marine Reef Salt. It has the yellow lid, says that it's the Advanced Formula, enhanced with additional calcium, magnesium and strontium. Phosphate free and nitrate free. My LFS suggested to me and said that I shouldn't have to add any supplements to my water.
I use oceanic salt which (said earlier by someone else) keeps calcium up but alk not so high so i've been starting to use reef advantage calcium and reef builder, testing with sera test kits before and after dosing 2x a week
Its easiest to balance the new salt mix prior to adding it to the tank for water change. Probably a good idea to check it on a per bucket basis since salt has been real inconsistant lately.
My earlier post should have said - Test each brand of salt one time, this will give you baseline. I got in deep trouble with oceanic salt assuming it was fine. Most salt is not ment for RO water - this will cause variation in mix from brand to brand. There are salts for RO water. I use Red Sea Coral Pro, nice stuff.