A liquid dispenser for dispensing at least one effluent mixture comprising: a manifold inlet connectable to a pressurized liquid source; at least one actuated valve defining a diluent outlet (66a, 66b) in fluid communication with the manifold inlet; at least one backflow preventer and eductor system (20a, 20b) in fluid communication with the at least one diluent outlet and defining at least one dispenser outlet for dispensing the at least one effluent mixture, the at least one eductor system defining at least one additive inlet in fluid communication with at least one respective additive source; a flow regulator (67a, 67b; 125; 215) in fluid communication with the at least one individual diluent outlet (66a, 66b) and the at least one backflow preventer and eductor system, the flow regulator located upstream of the at least one backflow preventer and eductor system and downstream of the at least one individual diluent outlet; wherein the flow regulator (67a, 67b; 125; 215) is individualized for the at least one backflow preventer and eductor system (20a; 20b) and is interchangeable within the dispenser to facilitate a plurality of volumetric flow rates to the at least one backflow preventer and eductor system; wherein the at least one backflow prevention and eductor system comprises an air-gap eductor in fluid communication with the diluent outlet and defining a dispenser outlet for dispensing the effluent mixture, the air-gap eductor defining an additive inlet in fluid communication with at least one additive source; and wherein the flow regulator (125; 215) defines an exit and is disc-like in shape and is permeated to provide a flow rate of liquid there-through via a restriction of the liquid's volumetric flow, the flow regulator defining an outer periphery sized for insertion into an entry end of a standpipe, the standpipe having a predetermined length and cross-sectional area, to define a flow regulator and standpipe assembly, the flow regulator and standpipe assembly is interchangeable and in fluid communication with the diluent outlet and air-gap eductor, the flow regulator and standpipe assembly located upstream of the air-gap eductor and downstream of the diluent outlet, the predetermined length of the standpipe defining a predetermined distance of 23mm (0.9 inches) between the flow regulator exit and an exit of the standpipe assembly to provide a laminar flow of liquid into the eductor, the standpipe exit being located proximal to an entry of the air gap eductor and downstream of the entry end of the standpipe. a manifold inlet connectable to a pressurized liquid source; at least one actuated valve defining a diluent outlet (66a, 66b) in fluid communication with the manifold inlet; at least one backflow preventer and eductor system (20a, 20b) in fluid communication with the at least one diluent outlet and defining at least one dispenser outlet for dispensing the at least one effluent mixture, the at least one eductor system defining at least one additive inlet in fluid communication with at least one respective additive source; a flow regulator (67a, 67b; 125; 215) in fluid communication with the at least one individual diluent outlet (66a, 66b) and the at least one backflow preventer and eductor system, the flow regulator located upstream of the at least one backflow preventer and eductor system and downstream of the at least one individual diluent outlet; wherein the flow regulator (67a, 67b; 125; 215) is individualized for the at least one backflow preventer and eductor system (20a; 20b) and is interchangeable within the dispenser to facilitate a plurality of volumetric flow rates to the at least one backflow preventer and eductor system; wherein the at least one backflow prevention and eductor system comprises an air-gap eductor in fluid communication with the diluent outlet and defining a dispenser outlet for dispensing the effluent mixture, the air-gap eductor defining an additive inlet in fluid communication with at least one additive source; and wherein the flow regulator (125; 215) defines an exit and is disc-like in shape and is permeated to provide a flow rate of liquid there-through via a restriction of the liquid's volumetric flow, the flow regulator defining an outer periphery sized for insertion into an entry end of a standpipe, the standpipe having a predetermined length and cross-sectional area, to define a flow regulator and standpipe assembly, the flow regulator and standpipe assembly is interchangeable and in fluid communication with the diluent outlet and air-gap eductor, the flow regulator and standpipe assembly located upstream of the air-gap eductor and downstream of the diluent outlet, the predetermined length of the standpipe defining a predetermined distance of 23mm (0.9 inches) between the flow regulator exit and an exit of the standpipe assembly to provide a laminar flow of liquid into the eductor, the standpipe exit being located proximal to an entry of the air gap eductor and downstream of the entry end of the standpipe.