Some people seem to have the opinion that bio-media coated with detritus is OK.
I believe that debris on bio-media needs to be regularly cleaned off, or the bacteria become smothered in gunk. These bacteria are facultative aerobic chemotrophs that "feed" on ammonia and nitrite on a molecular level. And if they (as biofilm) are mired in mud (and it doesn't take much for something the size of bacteria) to compromise their feeding ability.
This is also why beside the normal squeezing out of mechanical media, I also shake mesh bags of bio-media out when doing a water change.To keep the "good" bacteria robust, they need access to oxygen rich, flowing water.
In order for them to utilize the molecules, the organic gunk needs to be broken down to a much more than it is as visible stuff to the naked human eye.
When I worked as a microbiologist, we would find very robust nitrosomonas and nitrobactor colonies living in an almost "organic debris free" drinking water distribution system , living off the ammonia part of chloramine we used as a disinfectant.
I believe that debris on bio-media needs to be regularly cleaned off, or the bacteria become smothered in gunk. These bacteria are facultative aerobic chemotrophs that "feed" on ammonia and nitrite on a molecular level. And if they (as biofilm) are mired in mud (and it doesn't take much for something the size of bacteria) to compromise their feeding ability.
This is also why beside the normal squeezing out of mechanical media, I also shake mesh bags of bio-media out when doing a water change.To keep the "good" bacteria robust, they need access to oxygen rich, flowing water.
In order for them to utilize the molecules, the organic gunk needs to be broken down to a much more than it is as visible stuff to the naked human eye.
When I worked as a microbiologist, we would find very robust nitrosomonas and nitrobactor colonies living in an almost "organic debris free" drinking water distribution system , living off the ammonia part of chloramine we used as a disinfectant.
