We leave our feed/scratch/DE in the bags in the cans throughout the year. Since I'm the main care-provider, it just makes it easier for me to deal with when the bags get low (we buy feed and food grade DE by the 50# bags, I'm just over 100#'s).
I had thought about just dumping the feed directly in the galvanized cans that we use but I figured that keeping all of that in the bags makes sure that I'm feeding the oldest stuff first, without any of the feed getting stale (by being buried by adding the new feed), if that makes sense?
Dawn