Non-chlorinated concentrated acid detergent compositions and methods for using the same are provided. More particularly, the acid detergents comprise a quantity of a fatty alkyl-1,3-diaminopropane or salt thereof and optionally alkylsulfonic acid. The detergents form the basis for an all-in-one cleaning, sanitizing, and descaling composition for use on soiled surfaces, particularly surfaces contaminated with milk soils and other food soils.