Phosphate and Sulfer are both Acid forming Minerals !
Edit: Phosphoric Acid is made from Phosphates !
And Sulfuric Acid is made from Sulfer !
And these are Both Cationic in Nature and have a much Greater amount of Millhouse units of Energy than an Anion may have, thus the Reason "WHY" it may take much more Alkaline Minerals to Balance out these Acids in a Reaction with them! End of Edit.