One of our customers had the idea of putting the initial set of small cartridges aside after the initial charging so that they would be available as spares. After charging, they put in a set of the bigger carts and will use the small initial cartridges during the period when a large one runs out and a replacement can be ordered, when cartridge levels are too low to do a cleaning, etc. They are storing the opened small cartridges in air tight bags to protect them. Does anyone see a downside to doing this? The upside is that it is much less expensive than keeping a full set of larger cartridges as backups.