I have a 3 day method.
Put aquarium water in tote. Clean filter media in tote. I then fill one gallon zip-locks with the coffee. I put the bag next to the intake of the canister and crack open a corner of the bag to slowly squeeze the good stuff into the new filter. It is now seeded.
Run your old filter (with the old media) for a few days and repeat the process one more time.
Never lost a fish this way. Running 2 filters at the same time makes it harder to seed the new canister. Bacteria only grows to the amount they have to eat. That’s why it’s good to start the new one with filth from the old one. It just moves existing BB to a new home. None of it leaves the aquarium.