I agree with this. Some bacteria are good and some or bad. In addition the biofilm is not just bacteria. Algae and fungus is also part of any biofilm. I would expect some to be beneficial and some biofilm to be harmful.
Agreed. There does seem to be some symbiosis, but to what extent and how valuable it actually is, is half the reason why I would like to eliminate it in the tank, so that it all resides in the filter. The only harmful aspect, that seems to be the most obvious, is that biofilm also harbors algae, which is the main point of interest.
As to your experiment idea I don't think it is practical to do. there is always some bacteria, algae and fungus floating in the air. So as soon as you stop sterilizing microorganisms will move back in. So as soon as you stop the sterilization process new bacteria and organisms will move back in. The only way to permanently elliminate biofilm would be to completely and permanently seal the tank. During the sterilization process the plants will suffer some damage from either the sterilization agent or by changes in nutrient levels caused by the sterilizing agent reacting with minerals. That damage could favor a harmful biofilm over a beneficial biofilm. I can't think of any way to kill off a biofilm without doing some, even a small amount, of damage to plants. Also while Glut or H2O2 are affective against many organisms there will always be some organisms that will resistant or immune to the Glut or H2O2.
Well, I’ll find out how practical it is as I’m willing to risk damaging the good (with a very brief sterilization) to see if it results in a long-term reduction of the slow accumulation of algae on older leaves. I’m hoping that the glut will simply degrade the biofilm to help the UVS complete the job. I know that bacteria/archaea cannot be eliminated from the environment. The question is: once their biofilm cities are removed from the plant leaves, will their biofilm cities in a filter consume so much food that they all have to pack up and move there.
My reasons for posting those were more in response to your stated idea of adding more biomedia to filter.
In my case, I’m adding biomedia where none now exists. Regardless of your reasons for posting, it was a fascinating and eye-opening read. I do plan to test the possibility that cycling in pH above 7 will prevent AoB from forming and will actually require re-cycling when pH drops below 7 to create the AoB that exists only in NH4 environments (according to the studies you provided). I’m thinking of cycling at pH 8-9, developing only AoA, then dropping pH to 6.5 to see if total ammonia appears, indicating that the AoB aren’t there. Of course, one question is: will the AoA survive long enough to allow the AoB to replace it without a total ammonia spike?
And yes, all plants and even biofilm itself on rocks etc have ways of preventing Algae/Cyanobacteria from forming there. That is a discussion that isn’t even open for debate with me. But the intricacies of what causes us to make that system fail in our little closed loop/restricted slices of ecosystem is fair game.
I’m beginning to think that biofilm does not prevent algae from forming and, in fact, does the opposite. The articles provided by @jeffkrol
(and other articles I found after pursuing this line) indicate that algae actually become part of the biofilm (another one of the intricacies that you mentioned). Perhaps this is the long-term problem with algae formation on older leaves. Perhaps, too, the biofilm prevents allelopathic response by the plants (if they exist) from working.
I'm also starting to think that this entire thread is really getting out on the fringe of reality.