Salinity, redsea salt, aquaforest or reefer's best.
I personally use Instant ocean....it's true that you will have to run your alk somewhere between 7-9 when using a probiotic system like zeovit or biopellets but I found once you have your system stable around 8 it doesn't really affect anything when you water change with water that's higher in alk, I fell like it almost gives my coral a boost of energy to grow even more. But of course that's from my own personally experience and I am cheap.
