Once again THANK YOU Susan. I think its funny that people take things as fact because they read it on the internet and several people they talk to do it and say its so. I will not believe that a long tank or a tank with a large foot print will not have as much if not more BB in its substrate alone now add in any rocks, driftwood and even plastic plants along with some in the water column. I agree if you have a tall tank with a small foot print that there wont be as much BB in the substrate and now throw in a bare bottom tank and you will have almost no BB in the tank. I really dislike it when people make statements that almost all the BB is in the filter and will even state percentages because as far as I know there havent been any scientific studies done.
I know everybodies tank and maintenance routine is different and we all should do what is best for our own tanks but we all need to be carefull about stating facts on subjects like this at least IMO.