That's correct, except for the pre-charge thing. I can't remember the brand name, I'm at work, but it has a jar that the powder is put in and a filter element that the powder charges, Easy peasy, just put 3 TBS in the jar, screw it on, hang the unit on the aquarium and turn it on
I found a pic of mine. It's a "System I Diatom Pressure Filter"
Works very well, sometimes the drive belt gets a little noisy, but it doesn't bother me and it's only for a couple of hours.
Just let me know if you want to borrow it, Tim. You can get a 10oz. can of powder from Big Als.