Just to share a tip when refilling carto, when the carto is full and the excess drop is dangling at the base of the carto, take anothe carto and place it below the refilling carto to collect the drop, blow out remaining excess juice to the 2nd as well, do it with the carto at an angle so that juice will not flow into the aiflow passage. This helps to save juices(although the amount is very minimum), it also save us the trouble of finding a tissue paper to wipe the excess drop out juice.