A method for producing a dialysis liquid for use in extracorporeal blood treatment in a device for extracorporeal blood treatment, comprising the steps conveying water, preferably osmotic or high-purity water, via a main line (S2); conveying a basic fluid and introducing it into the main line at a first introduction point formed as a first Venturi mixer (S3.1); conveying an acidic fluid and introducing it into the main line at a second introduction point formed as a second Venturi mixer or at the first introduction point formed as a first Venturi mixer (S4.1a); measuring at least one physical and/or chemical parameter, preferably the conductivity, of the water/fluid mixture, which consists of water, the acidic fluid and/or the basic fluid, by means of a first measuring device , preferably a conductivity probe (S3.2, S4.2a); and adjusting the delivery rates for the water, the acidic fluid and/or the basic fluid by a control and regulation unit as a function of the measured value detected, wherein the measuring of the at least one physical and/or chemical parameter is performed by means of the preferably single measuring device located at a section of the main line downstream of the introduction point for the acidic fluid and of the introduction point for the basic fluid; and the control and regulation unit at least temporarily controls the introduction of the acidic fluid and/or the basic fluid such that over a predetermined period or a predetermined interval only one of the acidic and basic fluids is introduced into the main line , characterized in that the delivery and introduction of the basic fluid and the delivery and introduction of the acidic fluid takes place alternately, in particular in continuous alternating fashion (M1). conveying water, preferably osmotic or high-purity water, via a main line (S2); conveying a basic fluid and introducing it into the main line at a first introduction point formed as a first Venturi mixer (S3.1); conveying an acidic fluid and introducing it into the main line at a second introduction point formed as a second Venturi mixer or at the first introduction point formed as a first Venturi mixer (S4.1a); measuring at least one physical and/or chemical parameter, preferably the conductivity, of the water/fluid mixture, which consists of water, the acidic fluid and/or the basic fluid, by means of a first measuring device , preferably a conductivity probe (S3.2, S4.2a); and adjusting the delivery rates for the water, the acidic fluid and/or the basic fluid by a control and regulation unit as a function of the measured value detected, wherein the measuring of the at least one physical and/or chemical parameter is performed by means of the preferably single measuring device located at a section of the main line downstream of the introduction point for the acidic fluid and of the introduction point for the basic fluid; and the control and regulation unit at least temporarily controls the introduction of the acidic fluid and/or the basic fluid such that over a predetermined period or a predetermined interval only one of the acidic and basic fluids is introduced into the main line , characterized in that the delivery and introduction of the basic fluid and the delivery and introduction of the acidic fluid takes place alternately, in particular in continuous alternating fashion (M1). <EOS>