Live rock above the waterline

[M.E.Milz]

I have a wet/dry sump on my FOWLRADSB (Fish-Only With Live Rock And Deep Sand Bed) tank that has some bio-media (CPR's bio-bale) that has been left in to capture bubbles from my skimmer. I would like to remove the remaining bio-media and replace with live rock. I figure the live rock will catch most of the bubbles.

However, because of the way my sump is configured, some of the live rock will be above the waterline, although it will be kept wet by the constant flow from the trickle plate. Will the anaerobic bacteria eventually die-off in the rock that is not completely submerged? If so, then won't the live rock end up performing no better than the bio-media it replaced?

Thanks in advance, Mike

 

[Anonymous]

Put your LR in a plastic bag and break it with a hammer. Then put it in the sump fully submerged.

Dan

 

[M.E.Milz]

I can do that, and probably will do that (break up the rock so that it fills my sump completely). But my question is really directed to the extra rock that will end up above the waterline. Is this extra rock a waste because it won't function anaerobically? If so, then it only makes snese to add as much rock as can be submerged. If not, then I would be inclined to add the extra rock (which I want to keep on hand for future uses). Any thoughts?

One of the reasons why I am asking this is because my sump has a recirculating compartment where a portion of the water from my return pumps is fed to a trickle plate above a center compartment of the sump. I can eliminate this portion by cutting off the flow to the trickle plate. But I don't want to if this contributes some benefit to tank filtration.

 

[Anonymous]

Milz, from what I've read, live rock doesn't play as big a part in anaerobic nitrate reduction as does deep sand and algae harvesting and even water changing. So I think the minimal amount that was deep within the rock to begin with might die off, but that shouldn't change things much as the real anaerobic is handled by other components.

 

[jmeader]

I can't say how LR stacks up against a DSB for nitrate reduction. However, having maintained several Berlin systems using only LR for denitration I can say without a doubt it is effective. To answer your question I believe 2 things will happen with the exposed LR. The first will be that oxygen will penetrate deeper and destroy the current anaerobic area. 2nd the anaerobic area will redevelope deeper in the LR. So in the end I believe that it will be of some benifit.

 

[Mouse]

Stinky stinky,

 

[speck]

Hi M.E.Mills

If I understand you correctly, the rock is in an aerobic enviroment <BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quoteI figure the live rock will catch most of the bubbles. <BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote Which anaerobic bacteria would not be in.

Anaerobic (denitrifying) bacteria live in oxygen depleted, or oxygen free enviroments.
In our tanks, we have oxygen depleted (anoxic)zones where denitrifycation takes place.

BTW in anaerobic(oxygen free) zones anaerobic bacteria produce hydrogen sulfide. That rotten egg smell

LR in aerobic zones will support nitrifying bacteria which is good.

 

[M.E.Milz]

Thanks for the comments.

The consensus seems to be that I can add extra live rock to my sump above the waterline, but there will be some die-off of anaerobic bacteria within the rock, and the benefits of the extra rock will be minimal.

Is it also everyone's consensus that I scrap the recirculation portion of the sump? Perhaps I can add some sort of macroalgae that will grow in this wet, but not submerged area of the sump. Any ideas? I really hate to just scrap this feature of my sump. Perhaps convert it into some sort of algae scrubber?

By the way, I do have a lot of live rock and a 4"-6" DSB in the display tank.