A method for mixing and dispensing two substances, comprising: providing a first container containing a first substance; providing a second container containing a second substance, the second container having a top including an input neck and an output neck, each of which is sealed by a sealing device; providing an input pipe disposed inside the second container and attached to the sealing device at the input neck; providing an output pipe disposed inside the second container and attached to the sealing device at the output neck; providing a pumping system, the pumping system comprising: a pump having a pump slot; a main tube; a first valve on the main tube between the first container and the pump; a second valve connected between the first valve and the pump; a third valve on the main tube between the pump and a feeding tube; and a fourth valve connected between the pump and the input neck, the main tube comprising: a first tube section connecting the first valve and the second valve; a second tube section connecting the second valve and a first Y-connector; a third tube section connecting the output neck and the first Y-connector; a fourth tube section connecting the first Y-connector to a second Y-connector through the pump, the fourth tube section positioned in the pump slot; a fifth tube section connecting the second Y-connector to the fourth valve; a sixth tube section connecting the second Y-connector to the third valve; and a seventh tube section connecting the fourth valve to the input neck; operating the pumping system to combine the first substance with the second substance by pumping the first substance (S 1) from the first container into the second container; operating the pumping system to circulate the combined substance to generate a mixed substance; and operating the pumping system to dispense the mixed substance. providing a first container containing a first substance; providing a second container containing a second substance, the second container having a top including an input neck and an output neck, each of which is sealed by a sealing device; providing an input pipe disposed inside the second container and attached to the sealing device at the input neck; providing an output pipe disposed inside the second container and attached to the sealing device at the output neck; providing a pumping system, the pumping system comprising: a pump having a pump slot; a main tube; a first valve on the main tube between the first container and the pump; a second valve connected between the first valve and the pump; a third valve on the main tube between the pump and a feeding tube; and a fourth valve connected between the pump and the input neck, the main tube comprising: a first tube section connecting the first valve and the second valve; a second tube section connecting the second valve and a first Y-connector; a third tube section connecting the output neck and the first Y-connector; a fourth tube section connecting the first Y-connector to a second Y-connector through the pump, the fourth tube section positioned in the pump slot; a fifth tube section connecting the second Y-connector to the fourth valve; a sixth tube section connecting the second Y-connector to the third valve; and a pump having a pump slot; a main tube; a first valve on the main tube between the first container and the pump; a second valve connected between the first valve and the pump; a third valve on the main tube between the pump and a feeding tube; and a fourth valve connected between the pump and the input neck, the main tube comprising: a first tube section connecting the first valve and the second valve; a second tube section connecting the second valve and a first Y-connector; a third tube section connecting the output neck and the first Y-connector; a fourth tube section connecting the first Y-connector to a second Y-connector through the pump, the fourth tube section positioned in the pump slot; a fifth tube section connecting the second Y-connector to the fourth valve; a sixth tube section connecting the second Y-connector to the third valve; and a first tube section connecting the first valve and the second valve; a second tube section connecting the second valve and a first Y-connector; a third tube section connecting the output neck and the first Y-connector; a fourth tube section connecting the first Y-connector to a second Y-connector through the pump, the fourth tube section positioned in the pump slot; a fifth tube section connecting the second Y-connector to the fourth valve; a sixth tube section connecting the second Y-connector to the third valve; and a seventh tube section connecting the fourth valve to the input neck; operating the pumping system to combine the first substance with the second substance by pumping the first substance (S 1) from the first container into the second container; operating the pumping system to circulate the combined substance to generate a mixed substance; and operating the pumping system to dispense the mixed substance.