The biofilm grows there, and has very little to do with the nitrogen cycle or particulates in the water. There isn't much that can be done to prevent it, other than cleaning it off regularly so it never gets thick enough to break loose.
Originally posted by OrionGirl The biofilm grows there, and has very little to do with the nitrogen cycle or particulates in the water. There isn't much that can be done to prevent it, other than cleaning it off regularly so it never gets thick enough to break loose.
I have prefilters on 2 of my setups, and I really like them since it's much easier to pull them off and clean them without impacting the bacteria bed on the media within the filter. They are definitely beneficial for some applications.