The present invention concerns a dialysis acid precursor composition for use during preparation of a dialysis acid concentrate solution and for mixing with water a sodium containing concentrate and a bicarbonate containing concentrate into a ready for use dialysis solution. Said dialysis acid precursor composition consists of powder components comprising glucose at least one dry acid and at least one magnesium salt and optionally potassium salt and calcium salt. According to the invention said glucose is present as anhydrous components in said dialysis acid precursor composition and said at least one magnesium salt is present as magnesium chloride 4.5 hydrate (MgCl � 4 �5HO).
