is used to allow air to enter the detergent cartridge 20 as the substance contained therein is withdrawn a level indicator not shown in this figure may also extend through the vent opening 27 to measure the amount of substance remaining in the detergent cartridge 20 a barcode 25 identifies that particular substance within the detergent cartridge 20 the substance within the detergent cartridge 20 is withdrawn through a delivery tube 35 the delivery tube mates with the detergent cartridge 20 via a dispensing tube adapter 36 as the detergent cartridge 20 is inserted into the dispensing system the delivery tube 35 mates the delivery tube adapter 36 which is integrated into the detergent cartridge the level indicators are inserted through the vent and are used to determine the amount of substance remaining in the particular cartridge a float moves up and down depending on the level of the substance fluid in the cartridge in other words as the substance is removed from the cartridge the float travels downward sensors determine the location of the float and through this the relative amount of substance left in the cartridge in a particular embodiment the dispensing system includes fluid pumps the fluid pumps are in fluid connection with the cartridges via delivery tubes each fluid pump 50 is in electrical connection to a circuit board such as a motherboard of the dispensing system or.