If you use the Home Fill System then you have to fill the full pack of 16 Flowersticks. However you can also remove single sticks at a time and handfill them instead. Please see How To Fill Your Flowersticks videos on Omura.com. If you have removed any of the sticks from a 16 pack then the remaining sticks cannot be filled using the Home Fill Machine. We recommend keeping a separate pack for single stick fill use if preferred.