[Myka]

Albert, there is no argument to be had that there will only ever be enough nitrifying bacteria to compliment that amount of available ammonia. A person could not argue that. My experience is that there is often a lack of anaerobic bacteria for which there could be many reasons (poor rock density, rocks too small, etc). The sand bed is not usually a host to anaerobic bacteria unless a person has a very healthy, well-functioning DSB which is a rare thing for sure. For these reasons, it is definitely possible that more rock would provide more options (and thus more likelihood) for anaerobic bacteria populations which could then have a nitrate-lowering effect compared to a tank with a lack of anaerobic bacteria.

Coralgurl, go check out sphelps' tank journals for pics of really nice, clean, and organized sumps, cabinets, and fish rooms. I can never keep that tidiness up...