Please follow the Long-Term Storage instructions in your user manual. For pleated filter cartridges, you would mix up a bleach-water solution of 2 tbsp of bleach to 1 quart of water; pump through the entire water filter (including hoses) and then remove the filter cartridge and allow everything to thoroughly air dry before putting away.
For ceramic elements, pump a quart of clean water (tap water, distilled, etc) through your entire water filter (including hoses). Remove your ceramic element and allow it to very thoroughly air dry before putting away.