Mobile Bay Reef Keepers

I went with a semi deep sand bed on both of my "rookie" tanks. The reason being partly costs and the other being skepticism. Well, after finally cleaning both tanks to the bottom, I realize, a DSB is not the way to go!! Unless you have ever cleaned your tank to the bottom then you would not know what I am talking about. I started thinking that it wasn't such a good theory every time I had to move something off the bottom(when things where still "normal"). Every time the sand bed is even aggitated a small bit, poof, there's a large cloud of nasty. Well, after breaking two tanks down I realize the SKUM that is ALWAYS at the bottom of our tanks. It looks like a years worth of skimmate poured in all at once. Don't get me wrong here, I had PLENTY of bio-stirrers, I even stirred it up by hand before a water change. I think that at this moment, I would challenge the utmost authority on sandbeds as to what their actual benefiet is!! Sure their is more biological processes going on with all that sludge, but is it worth it? There is NO way that what I cleaned out of my tanks is "a good thing". I also question the "Berlin Method" theory. Liverock is great, it is a natural backdrop and supposedly filters our water. One problem, liverock collects everything that is not filtered. You would have to have a huge turnover rate just to keep the pores in the rock clean from detritus. This never happens. I see where the rock can grow beneficial life forms that feed our reefs, but to go as far as to say it is one of the best forms of filtration for the home aquarium is nonsense. A SMALL fluidized bed filter will give you tons more surface area than any amount of rock you can buy. Meaning it can harbor millions more bacteria. I am just re-thinking everything I have learned. Don't get me wrong, I had great success with my setup, but as most, if not all of you have experienced, there was something not "totally" correct, or everything would look great one day and then horrible the next, the off and on thing. All this junk at the bottom has to have something to do with it. What do ya'll think??

something interesting that I have been considering...
Its worth a shot and seems to be working Great for them....

http://www.garf.org/bulletproofreef/bulletproof.asp


Actually the entire website is kinda interesting to read...

http://www.garf.org

I know you do your research so this may be something you have already seen, but I though Dr Ron Shimek's article a few years ago ( and recently too) pretty much summed it all up.

DSB do a ton of good IMO. The produce foods for SPS, The provide benefitial nitrate reduction and on and on.

In answer to all that mess you found in your DSB, that is really totally expected and natural. here is a little about that from the provided link and article .

"Problems:

More imagined than real problems bedevil keepers of sand beds. The imagined problems are proposed by people who are ignorant of the sand bed dynamics. Among these imaginary problems are accumulations of hydrogen sulfide and detritus, and the need for sifting. Hydrogen sulfide will indeed be formed in the lowermost layers of a deep sand bed. It will NOT migrate up through the sediments to poison a tank. Hydrogen sulfide is an amazingly toxic gas, but that toxicity is exceeded by its pungent rotten-egg odor. The gas will have an exceptionally strong odor, and will seem overwhelming at levels well BELOW toxic amounts. If you can smell this stuff without it literally taking your breath away, it won't be at a harmful concentration. There is no real evidence to indicate that it may reach toxic levels in a deep sand bed.

Detritus build up in the sediment is another non-problem. If the sediment fauna is thriving, there will be a slight build up of fine detritus while the rest will be processed by the infauna. The final imaginary problem, the presumed need for sifting in a healthy sand bed, simply does not exist. Small organism movements "sift" the sand sufficiently. Any other sifting of a healthy bed will cause serious harm.

Sand beds recycle materials and export many of the excess nutrients in an aquarium. Some excess nutrients are mobilized by becoming soluble through metabolic processes and need to be exported either as harvestable macroalgae or animals, grown in the main tank or a sump.

The only real problem with a sand bed is the reduction in diversity as the bed ages. This is caused by extinction and replacement problems because the volume of our beds is simply too small for some species to generate self-sustaining populations. This is remedied, by purchasing a detritivore or recharge kit or two every year or so to give a boost to the fauna. "





http://rshimek.com/reef/sediment.htm

Something to think about. Come to think of it, some of the best tanks I have seen were bare bottoms. I think they are not very realistic, but they had very nice corals with great colors. The more I think about it, That's the way to go. The ZEOVIT method concentrates on a low "nutrient" principle. I'm sure people have seen their before and afters. It's a simple principle, KEEP IT CLEAN. That's the way mother nature intends it. You do want the biological food that liverock can produce, you just have to keep the the system in balance. The whole "pod" thing comes to mind. Pods are great, if you have something that feeds on them. If not, they reproduce, crawl into a cave and die, thus becoming the sludge on the bottom. The same way anything does in a closed system. The reason bare bottoms do so well, is the fact that any waste can be easilky removed, not so with a sandbed

SaltnLime wrote:I know you do your research so this may be something you have already seen, but I though Dr Ron Shimek's article a few years ago ( and recently too) pretty much summed it all up.

DSB do a ton of good IMO. The produce foods for SPS, The provide benefitial nitrate reduction and on and on.

In answer to all that mess you found in your DSB, that is really totally expected and natural. here is a little about that from the provided link and article .

"Problems:

More imagined than real problems bedevil keepers of sand beds. The imagined problems are proposed by people who are ignorant of the sand bed dynamics. Among these imaginary problems are accumulations of hydrogen sulfide and detritus, and the need for sifting. Hydrogen sulfide will indeed be formed in the lowermost layers of a deep sand bed. It will NOT migrate up through the sediments to poison a tank. Hydrogen sulfide is an amazingly toxic gas, but that toxicity is exceeded by its pungent rotten-egg odor. The gas will have an exceptionally strong odor, and will seem overwhelming at levels well BELOW toxic amounts. If you can smell this stuff without it literally taking your breath away, it won't be at a harmful concentration. There is no real evidence to indicate that it may reach toxic levels in a deep sand bed.

Detritus build up in the sediment is another non-problem. If the sediment fauna is thriving, there will be a slight build up of fine detritus while the rest will be processed by the infauna. The final imaginary problem, the presumed need for sifting in a healthy sand bed, simply does not exist. Small organism movements "sift" the sand sufficiently. Any other sifting of a healthy bed will cause serious harm.

Sand beds recycle materials and export many of the excess nutrients in an aquarium. Some excess nutrients are mobilized by becoming soluble through metabolic processes and need to be exported either as harvestable macroalgae or animals, grown in the main tank or a sump.

The only real problem with a sand bed is the reduction in diversity as the bed ages. This is caused by extinction and replacement problems because the volume of our beds is simply too small for some species to generate self-sustaining populations. This is remedied, by purchasing a detritivore or recharge kit or two every year or so to give a boost to the fauna. "





http://rshimek.com/reef/sediment.htm

I see many problems with his THEORY:

Hydrogen Sulfide
Admits this will be formed in the lowermost lyers, will not migrate up, amazingly toxic, no "REAL" evidence that it is toxic to sandbeds
Detritus Buildup
If fauna is thriving then there will be a buildup of detitus, sifting of "HEALTHY" bed causes harm
Exportation
Sandbeds recycle"MANY" excess nutrients, exported through macro algaes and animals
Extinction Theory???
"REDUCTION IN DIVERSITY", Beds are too small to self sustain certain species, "REMEDY" this by adding more every couple years

Now I'll answer.
Hydrogen sulfide. I don't know, but he says it's pretty bad stuff and it IS in our tanks. It won't migrate up, unless you have to move something. No evidence it's toxic, Where did he get that from and why even bring it up if it's not "TOXIC"
"If fauna is thriving there will be an abundance of detritus". Well, most of us have an abundance of fauna (all sandbeds do). "Sifting of healthy beds causes harm" The ocean,sea,gulf all stir NATURAL sandbeds constantly.
"Sandbeds recycle nutrients" HOW? OH, they feed algae that WE have to export.
"Reduction in diversity" THAT'S IT!!!! Only certain species will thrive in certain enviornments. So what happens to everybody else??? Who cares, we've got pods. What do they do?? Sure they are a snack, but how many of them reproduce and die without every seeing a fish?? SLUDGE ON THE BOTTOM

I see many problems with his THEORY:

Hydrogen Sulfide
Admits this will be formed in the lowermost lyers, will not migrate up, amazingly toxic, no "REAL" evidence that it is toxic to sandbeds
Detritus Buildup
If fauna is thriving then there will be a buildup of detitus, sifting of "HEALTHY" bed causes harm
Exportation
Sandbeds recycle"MANY" excess nutrients, exported through macro algaes and animals
Extinction Theory???
"REDUCTION IN DIVERSITY", Beds are too small to self sustain certain species, "REMEDY" this by adding more every couple years

Now I'll answer.
Hydrogen sulfide. I don't know, but he says it's pretty bad stuff and it IS in our tanks. It won't migrate up, unless you have to move something. No evidence it's toxic, Where did he get that from and why even bring it up if it's not "TOXIC"

Hehe, one of the top debated areas of reefkeeping, second only to lighting I think. The way I read it, he brought up the issue to counter the belief by many people that the "rotten" odor when removing DSB's is harmfull. What he is saying is the the smell is terrible even with negligable amounts of Hydrogen Sulfide, and that there is no evidense to support a link between sulfide contaminations and tanks using DSB. He, and many others, believe that with a true DSB ( 3-6 inches in larger tanks) that manually sifting of the bottom layer of sand is counterproductive and potentially harmfull.


"If fauna is thriving there will be an abundance of detritus". Well, most of us have an abundance of fauna (all sandbeds do). "Sifting of healthy beds causes harm" The ocean,sea,gulf all stir NATURAL sandbeds constantly.
"Sandbeds recycle nutrients" HOW? OH, they feed algae that WE have to export.

Yes, but as he states, the negligable amount of detritus are recycled into food for corals by detritus scavengers who feed onwaste and produce offspring, most of which are used as food by SPS, LPS and other filter feeders or becomes part of the food chain for macro organisms such as benifitial calepra algaes in a refugium. Remaining solid wastes are still removed via skimming. Just my opinion about the ocean and stirring sand beds, but I would think the layer of sand that is stirred by creatures and waves would be the thin top layer.

"Reduction in diversity" THAT'S IT!!!! Only certain species will thrive in certain enviornments. So what happens to everybody else??? Who cares, we've got pods. What do they do?? Sure they are a snack, but how many of them reproduce and die without every seeing a fish?? SLUDGE ON THE BOTTOM

true, diversity in the sand bed is reduced over time for varying reasons, one being overpopulation and the resulting inability of the sandbed to sustain certain organisms for lack of food. You can re-introduce new living organisms into the sand bed to recharge the biotope.

I think the truths and theories are sometimes intermixed. One thing that I realized in all my reading is that a DSB is benefitial but not necessary. It is not benefitial to have the DSB in the main tank though because they are nutrient sinks. A remote DSB that can be easily changed or taken off-line and vacuumed/stirred and filtered is the best route.

JMO.

Well, when I setup my 240G, this contraversy was being discused on RC... heres' why I ended up going with DSB:

1) I didn't want to do any maintenence on the bottom.
2) barebottoms looks un-natural which leads to #3.
3) I wanted a white sand bottom.
4) shallow sandbeds are dangerous, because they soak up nutrients, aren't deep enough to process it.
and 5) which is unscientific: Terry Moore. His tank is GORGEOUS, and uses a DSB.


Soooooooo

DSB is was for me.

I was lucky that I went with DSB too, because I end up putting a LOT of softies on the sand... bare bottom would have been a horrible decision for me, mostly based on asthetics. I wanted a reef tank, so that I could have something beautiful and self-maintaining, and w/out a DSB you just lost both of those attributes.

The problem there is that a SSB doesn't soak up any more nutrients than a DSB, it just doesn't process NO3.

As I said, I ran two DSB on different tanks. I never had a problem that I could directly link to the sandbed. I too love the looks of one. I am just saying that all this sludge slowly accumulates and it can not be a good thing. I can promise you this, If I filled up a glass with this "mud" and told you to put it in your sandbed because it is benieficial, you would tell me that I was nuts. It is all decayed organics, stuff we normally try to keep out of the tanks.

I definitely hear what you're saying about the lower portion of the DSB... that just means it's doing it's job really tho... I do make it a point not to ever re-use a DSB in another tank, I always start a fresh one with a little of seed "upper layer" from an established one.

FYI - Hydrogen Sulfide (H2S) is lethal to humans at >100ppm in air. I'd say it is pretty toxis stuff. The thing is that in water with a pH >7 (basic solutions) H2S is not really present because it reacts with the bases in the water to form a bisulfide molecule.

For the whole nerdy expanations: http://www.telusplanet.net/public/jcarroll/ION.HTM

And a quote if you don't want to read the whole thing:

"At low pH (acidic solutions), the predominant form of the sulfide species is the molecular H2S. This continues to be the case until a pH of about 6 when significant amounts of the bisulfide ion are present. Further increases in the pH results in the formation of more bisulfide. By a pH of slightly less than 7, there are equal amounts of the molecular and bisulfide forms.

At a pH of 8, the concentration of the bisulfide ion is about ten times that of the molecular H2S <that's a 90% conversion!>. The bisulfide ion is the dominant hydrogen sulfide species for pH greater than this value."

The bottom line is, even though H2S is a potential killer, in a fish tank the small amount "seeping" out of the sand will be convertered to a safe bisulfide. If you stir up your DSB, then you may have an instantaneous spike that can cause problems. But who would stir up their DSB?

I had a bare bottom on my last tank and I'm going with it on my new one as well. It just took a little vacuuming around the glass edge to keep it clean with high amounts of flow in the tank. As for the look i started to get my zoanthinds to cover the bottom. It never fully became covered becuase of Ivan but really started to look good. The areas not covered looked nice with different colors of coraline.

I know H2S all too well, we used to have to carry small filter breathers and a H2S meter on our belt out at the paper plant I worked at one time... nasty stuff!!!