E EliteFishy Fish Crazy Joined Aug 2, 2005 Messages 367 Reaction score 0 Jan 6, 2006 #1 How long does It take cor bacteria to colonize in a external filter?
Lynden a "fish hater" Joined Sep 19, 2005 Messages 3,557 Reaction score 0 Location Northern BC, Canada Jan 6, 2006 #2 Hours to days to weeks. It depends on several diffent factors.