Quote:
Originally Posted by daplatapus
If the bacteria on 150 lbs of rock is processing all the tanks parameters well, I do not understand why it would matter where the rock is. If someone really likes the look of sand flats and the creatures that lived there, what would stop them from having no rock in the DT and 150 lbs of it in the sump? As long as there is proper water flow and maintenance in both tanks, there's no reason why it wouldn't keep water parameters in proper alignment, no?
I'm not trying to be argumentative either, just curious for my own benefit and others following along. Help me understand  |
On top of what Brad said, take a look at this:
What I'm trying to illustrate is that no matter what amount of rock in your tank, its surface area will always pale in comparison with the of your substrate -- by a long shot!
One of the points I stress is that you don't get to pick where your bacteria go. They will always colonize surfaces best suited for their metabolism. In this case, surfaces that have:
1. proper texture
2. high oxygen exposure
3. high resource saturation.
The surface of sand allows for this more so than any measure of rock. So you will find the vast majority of biological activity within the top ~1/2" of sand, grade dependent. IMO, rock is mostly an aesthetic. Its filtration capacity, while good, are nowhere near the effectiveness that we give it credit for.
Regarding anaerobic processes: While it is true that this happens within your live rock, it's generally pretty minimal because of the ecology constraints I described in my earlier posts. That's why normal fish tanks struggle with NO3. Of course, there are bacterial solutions to this (probiotic/carbon dosing, zeovit, biopellets, sulphur denitrifiers, etc), but they are outside the scope of this discussion. I'm just pointing them out to cover my a$$ :P