Storms

[rwilliams26]

We routinely create a little underwater "storm" when we do water changes; by taking a turkey baster to the live rock and blowing off much of the settled detritus, etc... Here's my question: Is it advisable to disturb or "sift" the sand bed? Our tank is maturing (about 16 months), and we've got many small feather dusters growing up out of the sand. Would sand mixing release "harmful" bacteria, etc...? :-o

Just curious.

[JimD]

Hey Robert,
I wouldnt advise disturbing the sandbed in that way, yes, it could create harmfull bacteria to some degree. The best way to keep your sand clean is with Nassarious snails and Fighting conches. These creatures are searching for organic materials like detridus and the like to feed on, will not harm beneficial micro oganisms in the sand.

[lax]

I can say that I accidentally did that when I was transporting my tank, and it took about a month to recover. Maybe it took that long b/c its a nano, but still I would strongly advise against it.

[MikeP]

Not endorsing it per se but some european aquarists have had very good luck doing periodic 'detritus storms' in their tanks to get organic matter into the water. Some really good soft coral growth on some challenging species with this. Most are not using a deep sand bed that is in vogue at the moment and personally I would not. While stirring a small area near the top should be ok. If your sandbed is not processing waste efficiently (there is some debate now as to whether dsbs just sink the wastes) and has stagnant patches you run the risk of disturbing that and freeing trapped hydrogen sulfide which is lethal in a closed system like our tanks.

I use nassarius snails, a fighting conch and a black cucumber in addition to my rainford goby to keep my sand nice and clean - I do not have a deep sand bed, mine is mostly for looks and to anchor a few LPS and clams.

[GaryP]

I too have seen some authors mention the beneficial of feeding bacteria to corals by stirring the sand bed. Remember the top portion of a DSB should have fairly high oxygen levels. Sulfides should only be at the deeper levels of the DSB. Some corals, particularly leathers, feed primarily on bacteria. So I guess the answer is if you do stir your DSB it should only be done on the top layer.

On another note, Hydrogen sulfide is a gas, although highly water soluble, and this would be released at low concentrations from the DSB. At the pH's we operate most of it would be in the form of sodium sulfide. Organic sulfides should be removed fairly readily in a skimmer. I know a lot of us have had the experience of dealing with the strong sulfide odor of a mature DSB when moving a tank so I'm sure there is some build-up in the DSB.

OK, there's my 2 cents.

Gary

[matt]

Supposedly the sulfide odor is indicative of a poorly maintained sand bed. I've had it too, but I read recently that if there is a sufficient population of sand bed animals, the sand bed processes waste efficiently enough to keep hydrogen sulfide from accumulating, even in the areas of lower oxygen content. So, I'm trying to stock my sand bed as strongly as possible. I'm pretty sure that the problems some people are having with the long term aspects of a sand bed have to do with insufficient life in the sand. For a really functional sand bed, we need to avoid sand bed predators and periodically restock the sand bed via live sand innoculation. If the sand bed population is lost, the sand becomes a detritus trap, and hence the build up of toxic materials.

With regards to sifting the sand, if you are trying to maintain a functioning deep sand bed, meaning filled with micro-life, sifting the sand causes significant mortality, and is a definite no-no.

[Tim Marvin]

I wouldn't do it Ron.

[kaiser]

I got a bunch of "air" bubbles in my sand. You can see them where the sand meets the glass. What is that?

[Sherri]

I do also kaiser...was wondering the same thing?

[matt]

That's the sand bed at work, processing nitrate into nitrogen gas. Could also be some photosynthesis by cyanobacteria. Either way, it's normal.

[GaryP]

Sulfide is a natural product of the breakdown of organic waste. That's why you smell the "rotten egg" odor around a sewage treatment plant. Proteins contain sulfur groups that are broken down by bacteria into sulfides or mercaptans. Mercaptans are the compounds that are used to add odor to natural gas and are made from sulfide. Sulfur compounds are requred by all organisms as a nutrient. Sulfide is highly toxic, I guess the question is whether enough is present in a tank to be a problem. I think a lot of it is removed by being precipitated as Iron Sulfide in a sand bed. That's the black material that is sometimes seen in the deeper parts of a sand bed. Iron sulfide is inert at the pH's we operate at.

Gary

[rwilliams26]

Great information you guys! This is why I like it here. :D