Do Living Stones "work" if buried under sand?

[ralphie16]

The aerobic and anerobic bacteria on Living Stones is the basis of my biolgical filtration (along with my sandbed).

If you bury the stones under your sand, would it still have this ability? I would think the aerobic bacteria would mostly die (or move) and the stone would function almost completely as an anerobic environment, unless there is sufficient oxygen in the sandbed?

I am asking because even though I have a lot of living stone, I have about half of it buried under the sand to support the stones that are ABOVE the sand because I have gobies and shrimp that can undermine the rockwork and I was wondering if the living stones are ok under the sand.

 

[barbra]

I'll be brave and take a stab at this one......This answer is based on my reasoning power and not on any studies or anything like that. With that said....

I think it would be as helpful under the sand as it is on top of it, only in a different way. If the submerged rock contains organisms that need the flow and light of above sand living, then the rock, once put under the sand, would become colonized with things that live in that environment instead and would continue to do it's job.

 

[Randall_James]

I would be it loses a good portion of its ability. As the main function is to render nitrates to nitrogen, the lack of water flow over the rock would seem to inhibit this process.

but then again... am not a chemist

 

[barbra]

<a href=showthread.php?s=&postid=9280838#post9280838 target=_blank>Originally posted</a> by Randall_James
I would be it loses a good portion of its ability. As the main function is to render nitrates to nitrogen, the lack of water flow over the rock would seem to inhibit this process.

but then again... am not a chemist

Perhaps, but since the sand bed itself is probably quite able to take over the portion of filtration lost by burying the rock, and the rock were to take onto it's surface whatever bacteria live in the sand, wouldn't the net exchange probably be equal? ...Highly speculative of course.

 

[Randall_James]

Unless the sandbed is deep (5-6") I doubt that the nitrate levels will be addressed properly.

 

[ralphie16]

but isn't nitrate processing completed in the anerobic environment? this wont be effected then because this happens inside the rock anyways, so this will continue as before i would assume. now the aerobic bacteria would be affected the most because they are not getting sufficient oxygen without the water movement at the surface (since its buried), so ammonia and nitrite processing would be the only processed reduced. make sense?

 

[Randall_James]

the bacteria are not going to thrive if there is not adequate flow around the rock I would bet. If the rock is buried, the bacteria are going to consume the available 02 and the aerobic organisms are probably going to perish.

 

[boxfishpooalot]

I think they work better burried. I once had a rock underneath sand. Upon removing it a large N gas bubble released from it and reeked of rotten eggs, H2S. So yea I think they work better submerged. But beware of H2S.

 

[Sepeku]

Mine turn black, that is, the submerged part turns black.

You can re expose it to the "surface" and within about a day it turns the color of the rest of the rock.

So certainly something different is going on.