One thing I would suggest, if you have the carbon packets, save them for a time when you have to remove medications from the water. Fill the last compartment with a synthetic filler like crafters use to stuff pillows or things like that. You can get a huge bag pretty cheap and it works as a water polisher, cleaning out all the gunk the other sections miss (and there is a LOT that they miss).
Another suggestion; Use a thin film of petroleum jelly on the gaskets. It keep the seals moistened, helps prevent the seal from leaking, and is harmless to the fish.
I keep my canister sitting in a plastic tub just in case of a leak, but I haven't needed it... at least not yet.