The main benifit with HOB
filters are mechanical filtration (removal of detritus via a filter pad) and they create more flow. They also contribute to bio-filtration a little bit. You can also use them to run carbon if you like. If you have enough bio-filtration (LR
) with a good clean up crew you can skip the mechanical filtration. Seaham and I have different opinions on the use of LR
rubble in the sump. While it is true detritus can accumulate,the LR
rubble acts in the same manner as LR
in removing nitrates. Plus, I use a sponge over the intake of my sump line so it takes out the big chunks anyways. Seaham uses a sump without LR
to add water volume to the tank and store equipment. I am sure it does just fine. It is just a good example of how different techniques can yeild the same end. the choice is really yours.