A dialysis acid precursor assembly including a dialysis acid precursor composition of dry components including anhydrous glucose, a dry acid, a magnesium chloride 4.5-hydrate (MgCl2.4.5H2O) and a potassium salt or calcium salt, and a moisture-resistant container with a water vapor transmission rate less than 0.2 g/m2/d at 38° C./90% RH, wherein the dialysis acid precursor composition is sealed within the container.