I think it was close to 3 tablespoons of epsom salt added to a liter bottle of the Macro solutions.
500mls = 1/2 q liter, the instructions state 1 tablespoon of CMS+B, 1 table spoon of MgSO4, 1 Tablespoon of KNO3 and 2 for the K2SO4, but this can be replaced with GH booster unless you believe whacky K+ myths. The GH booster will add more MgSO4 and there's a little in the CMS, so you are about close to 1.5 table spoons per 1/2 liter, or 3 table spoons per liter of solution.
The break down in ratios and ppm's are listed there in the link.
Just do not mix PO4 into it.......keep that separate from CMS.
Macros and micros are typically what many dose if they use liquids.
PO4 dosing was not considered much at the time of PMDD due to the belief it caused algae. But many did dose small amounts to stave off strong limitations on plants.
I, on the other hand, dosed a lot and reaped the benefits not to mention the knowledge and the better understanding.