Depends on what you have as far as LR
to handle biofiltration. If the HOB
is a large source for you filtration, you should take some of the media from the 280 to seed the new filter with. Be sure the old media is placed before the new media (on the bottom) or it will take forever. You could also run both for a few weeks if there is room.
If the HOB
is not an intricate part of biofiltration, simpley swap the old for the new.