explain why please

Select all the descriptions below that accurately describe hardness removal by lime soda softening. Its practical limits for calcium and magnesium are 30mg/L and 5mg/LCaCO3, respectively. Magnesium hardness should be targeted for removal if it exceeds 40mg/LCaCO3. pH of the sample must be less than 8 to apply lime soda softening Its reagent requirements are dependent on the sample's total alkalinity, total hardness, magnesium hardness. calcium hardness, carbonate hardness, non-carbonate hardness, and carbonic acid content