This thread got me curious: converting old canister filter into refugium
Is live rock useful for high or forced flow situations (like in a canister filter as in the post above)?
As I understand it, where live rock has an advantage over other bio-mediums (bio-balls, bio-wheels, etc) is in its ability to process nitrates as well as ammonia and nitrites. I've heard this described in terms of an "oxygen gradient" where the near-surface parts of the rock will be oxygen rich because of high flow and contact with surrounding water and host aerobic bacteria. The inner rock then will host anaerobic, nitrate eating bacteria due to the lower water flow to the inside and due to oxygen being stripped from the water by the aerobic bacteria that the water first must pass by.
Right?
So say you fill a canister filter with live rock rubble. The filter will force water through the rubble at a much faster rate than if it were sitting in a display tank (even with high flow in the display). The rubble will also have a much higher surface area to volume ratio than a giant hunk of rock which will allow water/oxygen easier access to the inside crevices/pores of the rock, thereby reducing that oxygen gradient and so reducing anaerobic bateria.
Right?
So is there any point to using live rock rubble in a situation like this? Rather: would there be any advantage to using live rock rubble over an artificial bateria colonizing surface (like bioballs) in the same situation? Am I thinking about this correctly?
Is live rock useful for high or forced flow situations (like in a canister filter as in the post above)?
As I understand it, where live rock has an advantage over other bio-mediums (bio-balls, bio-wheels, etc) is in its ability to process nitrates as well as ammonia and nitrites. I've heard this described in terms of an "oxygen gradient" where the near-surface parts of the rock will be oxygen rich because of high flow and contact with surrounding water and host aerobic bacteria. The inner rock then will host anaerobic, nitrate eating bacteria due to the lower water flow to the inside and due to oxygen being stripped from the water by the aerobic bacteria that the water first must pass by.
Right?
So say you fill a canister filter with live rock rubble. The filter will force water through the rubble at a much faster rate than if it were sitting in a display tank (even with high flow in the display). The rubble will also have a much higher surface area to volume ratio than a giant hunk of rock which will allow water/oxygen easier access to the inside crevices/pores of the rock, thereby reducing that oxygen gradient and so reducing anaerobic bateria.
Right?
So is there any point to using live rock rubble in a situation like this? Rather: would there be any advantage to using live rock rubble over an artificial bateria colonizing surface (like bioballs) in the same situation? Am I thinking about this correctly?
