Hi HoopsGuru I guess I should have been more precise in what I said. By saying bugs I was refering to pods
, flat worms, britsle woorm, spagetti worms and so on that are bought normaly in the hobby. And yes they will not go into the anerobic zone. Of coarse bacteria will populate all levels of the sediment.
I have read the article that you posted beforew and just reviewed it again.
The fact that "all bugs will not go past the oxygenated zone" is flat out untrue
Hmmm this is true my friend, even the article you linked verifies it. With the exception of bacteria. The worm I linked is not a mystery worm its actually common in a DSB
that has had it introduced through sand swaps or LR
In a bed you have a areobic zone (totally oxygenated) here lies 98% of your critters, then comes the anerobic zone (greatly reduced oxygenated zone)This is basically the transitional zone where the bed goes from oxygenated to anoxic (no oxygen) this is a very thin zone (very thin) and is completely dependant on oxygenated water being introduced to it. If you have a ton of life in the areobic zone moving the sand you may be able to have a few critters from the areobic zone spend very short periods in it. But they are of no consequence to the function of the bed. Below this microscopic layer of the anerobic zone is the balance of the sand bed, the anoxic zone. Here thier are no crittters except bacteria. The worm I showed above is the only worm that has the ability to migrated from oxygenated area to the anoxic zone. They do so by basically holding thier breathe or they to will also die of oxygen deprivation. This movement allows Nitrates (the excretement of the areobic zone) the be pushed down to the anoxic zone. In turn by this movement they will allow the release of Nitrogen gas (and excretement of anocix bacteria).
If you re read the article you provided you should see that it says the same thing. The worm is the animal that transfers the nitrate down, you can still get a very small amount of this transfering with out the worm (basically from strong water flow over the bed) but it greatly reduces its functionability.