A lot of people store it in the refridgerator, but that's not always the best. CA activates from moisture, so you want to store in a completely dry airtight container. I have a set of Food saver vacuum containers that I can put the CA in and suck out all of the air to keep it completely dry. If you don't have that put them in an airtight container and drop in some of those silca dessicant packs you find in electronics boxes, if you don't have those put some rice in to soak up the moisture. Even a small airtight container with nothing else will do a good job of storing it, better than the fridge.

Hope this helps

Ken