Hi all. I've been following this thread because In the late 1990's I worked at a LFS and my boss was a fan of DSB. I learned of the function of one as a nitrate reducer without really understanding the science. I only knew the importance of not disturbing the anaerobic bacteria at the bottom and keeping a healthy colony of creatures at the surface. My question now is: where do the anaerobic bacteria come from when a DSB is put in? I assuming the creatures on the surface come from seeding a tank with LR but I am at a loss to imagine where the anaerobic colony comes from?
I'm not quite sure on this one but I would assume it's like any bacteria in that If the conditions are suitable in the environment, it'll just grow. Kinda like the bacteria that grows on meat or liquids that are left out too long. In this case suitable conditions are low oxygen. I could be very wrong though =\