No, you must use a filter bag. I found that it is easy to take out the strainer in the middle of the container (the cylinder w/holes that keeps the carbon from entering the propellor) and place the bag over the hole on the bottom. It will work. You could buy the purigen pre-packaged in a bag.
And yes, purigen is by far the best filter media out there. Period. I've been using the stuff for years, in the magnum 350s.