What are the Bubbles in the Deep Sand Bed?

[Mal]

I put in a deep sand bed of 4 to 5" of fine southdown play sand in my tank. After about 4 weeks I am starting to see bubbles of air about 1 inch down in the sand below the surface aganist the glass. When I mix the sand the bubbles come out of the sand and float to the top.

Where are the bubbles coming from? Is this a good thing?

Are these bubbles from the conversion of nitrates?

Thanks for the help.

Mal

 

[Reefguide]

Those bubbles are the point of the DSB... Denitrification !!

 

[Mal]

Why does denitrification not happen when you use the more coarse crushed coral? I was told to take the corse stuff out of my tank and put in fine sand.

Mal

 

[Minh Nguyen]

Why does denitrification not happen when you use the more coarse crushed coral? I was told to take the corse stuff out of my tank and put in fine sand.

Mal

It does. It just requires a deeper bed to reach near anaerobic condition required for de-nitrification if you use coarser sands.
Minh

 

[Entacmaea]

With the coarser CC, water is able to flow more freely trough the substrate, which prevents, in part, stratification of the sand bed. The finer sand (if deep enough) creates layers in the sand bed that, because of properties related to the differing amounts of oxygen and other nutrients available to them, harbor different bacteria that process nitrogen. While this is hotly debated to some, I think a DSB is a good thing, and your bubbles are natural. One more thing, I would probably avoid stirring your sand bed- it will disturb the above mentioned stratification. Your DSB critters should stir the bed enough for you...

Peter

 

[Mouse]

geeeese, and there was me thinking they were little worm farts. :lol:

Oxygen free denitrification from Nitrates to a nitrogen gas. The preceding stages of the denitrifying cycle are completed in an Oxygen rich zone of bactereal colonisation.

 

[Entacmaea]

Hey, but I bet worms fart nitro too- hence all those popping noices when you can't find a mantis or pistol shrimp! :lol: