herman

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solbby said:
In a paper that studied the amount of nitrate and phosphate in core samples, at 1 inch there is no detectable nitrate phosphate accumulation! (I have the paper on my work computer, so tomorrow I will post the findings, unless I can find it here on MR). However, as you go deeper nitrate and phosphate are present in increasing amounts.

So if you going to have a SSB I would not go beyond an 1 inch deep, so that no anaerobic bacteria can be present.
Does the paper say at what point the sand bed gets deep enough not to have a negative effect? Is there such a point?
 

ShaunW

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Here is what I posted on MR at the beginning of the year!
I did some additional reading, :) , and found the following. From one of the original papers that got the whole DSB vs BB going (Takayanagi and Yamada, Effects of Benthic Flux on Short Term Variations of Nutrients in Aburatsubo Bay, J. of Oceanography, vol 55, pp.463, 1999)
http://www.terrapub.co.jp/journals/...03/55030463.pdf
http://reefcentral.com/forums/showt...25&pagenumber=3

The concentration of ammonia increases with depth to 15cm and remains constant below that depth. The concentration of phosphate also increases with depth to a maximum value at 10cm and gradually decreases below that depth.

10cm = 5inches. At 2cm or below (1/2 to 1 inch sandbed) the phosphate level is minimal to non-existant, same with ammonia (from the paper, one of the holy grail papers in the whole DSB vs BB debate). Therefore, no DSB issues (leaching of phosphate or ammonia/nitrate) exist with the shallow sandbed of 2 inches or below.
 
D

DEEPWATER

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I have to say this is a great thread.As Im reading more and more ,my question are being answered as it gos on.I dont have much to add.Just that i hope others are reading and learning as well.I have a 2" SB with lots of critters,Also 20lbs of mud and 5 lbs of garf grung in my sump ..My tank as been running like for 2 yrs,What do you think ,am I in anyway going to have a crash from that?
Spykes Very interesting subject.Want to THK everyone for the info
hope i can ask these type of question on this thread
 

ShaunW

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Kedd said:
I love this thread!

There is alot to think about, and learn in this one.

I'm not going to fix it if it ain't broke(sandbead), but I may fix it before it does.
Mine is still very young, so if I decide to go BB I will do it in the summer when I can have the entire house open for the transfer.

But It may never happen,I do like my sand and all the critters.

Someone make up my mind for me! LOL:scratchch


Kedd
Kedd do not change a thing! Your tank and growth is fantastic.
 

herman

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DEEPWATER said:
I have to say this is a great thread.As Im reading more and more ,my question are being answered as it gos on.I dont have much to add.Just that i hope others are reading and learning as well.I have a 2" SB with lots of critters,Also 20lbs of mud and 5 lbs of garf grung in my sump ..My tank as been running like for 2 yrs,What do you think ,am I in anyway going to have a crash from that?
Spykes Very interesting subject.Want to THK everyone for the info
hope i can ask these type of question on this thread
Only in this hobby would one say "with two inches or less youre fine".... :approve:
 

ShaunW

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Some more information to the pot! :D

To get this debate really going I want to add a few tib bits first!

Please read!
Eric Borneman on Reeffrontiers:
"....the thing about algae is, as I think I mentioned, there is a nutrient component and an algae component. Algae, being fully autotrophic, will thrive in very low nutrients if there is no grazing. The reason they don't take over even oligotrophic reefs is the grazing pressure. Obviously, higher dissolved nutrients helps them grow faster - and in excess makes corals fare peooer - but algae almost always grow faster and outcompete corals were in not for grazing. Turfs are highly grazed, macroalgae less grazed and also depedning on how palatable they are and what other algae are present.

Fish tend to be most finicky, especially if they know there is food coming (like in tanks). many urchins are great unfinicky generalist grazers - even though if offered turfs or Dictyota, they will graze turfs first, they will eat Dictyota when there is nothing else left. A fish in a tank will probably think "screw the Dictyota, a lettuce clip will be along soon enough". Snails work, but nowhere near to the eficiency of urchins, and snails may not graze some algae, or they can lierally be killed by it. Some of the brown algae are very toxic, and urchins can detoxify them somewhat - as can some fish. I am not aware of snails that can do this.

Anyway, those types of organsims, including lettuce slugs, etc, are macrograzers. A large portion of grazing belongs to the micrograzers - basically amphipods. If you poke through a Derbesia patch, you'll see tons of amphipods. The idea here is to let the macrograzers do their work on the big unpalatable and out-in-the open areas and reduce the load on the amphipods who will take care of little new sprouts., stuff in the nooks and crannies, etc.

As to rock crevices being filled with detritus or purportedly acting as a nutrient "sponge" that leaches out nutrients, I don't really go for that idea. It's possble, but I think it is rare, esepcially if the carbonate source is not from some polluted coastal area. The porewater of rocks is loaded with critters and microbes that easily should be able to manage any organic deposits over time. They cycle....lots of detritus, low bugs leads to increase of bugs then decrease of detritus, then die off of bugs, and repeat. As for the idea of carbonate acting as a time-release capsule for dissolved nutrients, same thing - the life in the rock should handle it easily, and if the water is that nutrient laden, and the rock is also laden, and the water is changed to a pure form, and the nutrients seep out through porewater, it won't take that long in reef rock because of the porosity and small size of rock. Turnover time, by necessity if in low nutrient water and without any life present in the rock at all cannot exceed the length of time it took to get that way in the first place. Any leaching, provided it is not by solid material containing harmful elements being slowly dissolved, should be pretty quick.

Finally, I have spent a lot of time taking both live rock and dead coral skeleton and decalcifying it (using acidified EDTA). The amount of algae, worms and sponge in marine carbonate is ridiculous. Sometimes I think there is more sponge than carbonate. So, nutrient leaching could also just as easily come from the die-off, excretion and boring action of all these organisms. If you put a piece of live rock in a bare bottom tank and wait, you'll get a pile of detritus really fast. Where do you think this comes from? The surface? Well, a little from algal shedding and surface material and mucus, but the majority comes from borings and waste of those things inside the rock and released out the pores. Live rock is a very active thing, and the notion that it is a big carbonate sponge that sucks up all the nutrients and slowly releases them causing algae and/or posioning the tank I think is relatively rare. Porewater is greatly higher, normally, in N and P, and is largely oxidized or absorbed before it enters seawater. That aspect of it is what makes it functional and able to support the great amount of life in it.

Sometime when I decalcify some substrate, I'll take a photo of the substrate and the material left after decal....its really amazing. I'm not saying that it never happens, or that a mismanaged tank could not produce these results, but if the tankis mismanaged to that extent, those issues need to be addressed before one starts throwing out the sand or rock thinking its going to fix an algae problem. I can assure you that even a cesspool of a tank in the presence of leaching substrates and gross food inputs will have no visible algae in the presence of enough grazers. Not suggesting this, just making a point. "
 

ShaunW

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I said this in another thread also at the beginning of the year!

"I think that it comes down to finding the happy equilibrium between - not having an overabundance of "rotting" organic matter vs. enough organic matter to feed the fauna and flora present. Real reefs in the ocean have the most biomass/organic matter of any ecosystem on the planet, it is not a sterile environment!

Stagnant dendritis at the bottom of a starboard reef will rot and needs to be removed or resuspended. That same dendritis would be food for worms and other inhabitants in a DSB/Shallow sandbed.

The oligotrophic bacteria in suspension also probably need a happy medium, and their happiness must affect the entire tank. Too much is bad, too little, also bad.

I personally believe that the engineers responsible for the next latest and greatest skimmer (I can just hear them saying "We Need More Bubbles!!! MORE BUBBLES DAMIT!") forgot their biology classes if they ever paid attention in the first place (I didn't in engineering class, so I can't blame them, :) ). They should have asked the question during their R&D sessions, should we really remove every last particle of organic matter down to the last part per trillion, is that biologically helpful to an aquarium?

Once again it comes down to understanding the system that you setup and applying good husbandry methods to your specific system."
 

ShaunW

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The reason I said said the above is because of this! also from the distant past! :)

solbby said:
I found a very interesting journal article yesterday, its title is "Oligotropic Bacterioplakton with a Novel Single-Cell Life Strategy". The jist of the article is that it seems that oligotrophic bacteria (marine bacteria living in the low nutrient ocean) do not form biofilms (grow on rock/substrate, any surface present), but instead have a life strategy in the aquatic environment in which dispersal is promoted to optimize cell access to substrates. The free living bacteria have the option to explore the dissolved organic matter continuum lacking surfaces (a good source of food for the bacteria, which becomes a good source of food for corals). This environment consists of organic matter ranging from the size of monomers to strings and aggregates of biopolymers that produce a microscopic matrix in the water, which promotes single-cell dispersal instead of colony formation by bacteria.

So, the crud pulled out by our highly efficient skimmers is probably oligotrophic bacteria (better known as the "most successful organism on earth", and an extremely important member in the reef food chain).
 

ShaunW

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OK, enough fuel to the fire! Sorry for quoting myself (I just hate it when others do it), but alot of the background has been already said before here on MR!
 

herman

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Now the thread will be on fire. You do have a point though! On the one hand you have biologists with their deep undertanding with beautiful aged tanks and on the other hand you have giant skimmer junkies, with beautiful aged tanks. Amongst the two categories there are additionally two more categories. BB & DSB. Hopefully someday we can all find the equillibrium.

I happen to fall in the more bubble BB category because I dont fully grasp the biology side of things. That is something I can admit after all the papers I have read today. I struggled alright.
 

ShaunW

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Herman there will never be a happy equilibrium between BB and DSB! Both require extreme different husbandry skills.

The quote "If your going to step through the door, step through deeply." comes specifically to mind.
 

ShaunW

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House of Laughter said:
Herman, yes, splitting hairs though :) Davem scientifically, is there a way to buffer the HS2? what is it's natural enemy? O?

AND THE TANK IN IT'S DAY . . . .
Jim the answer to your question is IRON! The trouble with Fe is that it is toxic to SPS!
 

spykes

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well i have to say i completely agree with shaun on the equalibrium of organic matter within the ecosystem, where there will be just the right amount, but i have to say, are our tanks really suppose to mimic everything that happens in nature? the ocean water is completely not sterile, so is our tank water last i checked. My tang poops alot hehhe. IMO this is MO im going on, there should be enough organic matter within the rock to feed the nesscery funia. but adding a DSB allows our tank to contrap everything where our water quality will be brought down. i cannot agree on skimming out oligo is the key to lowing nutrient levels or any type of microfuna. but i find between having a efficent skimmer and high flow and bear bottom, my rocks's organic creates a efficent enough equalibrium between the tanks. I think we are not the ocean and shouldnt create the biological filtration that the ocean provides 100 percent. biology and chemestry works with our method of mechanical filtrations, i do not think our filtration should remove everypeice of organism or organic matter in the water, corals and life needs nutrients to feed on, many amino groups and bacterias that feed the coral exist at night. that is why i have put my timer to shut off at night. but i believe biological filtration also gives out way to many byproduct for itself to filtrate, that is why mechanical filtration is efficent as well. i dunno shaun, you got me very excited right now, because im registered for microbiology for next semester!!!!!! YAY!

Stagnant dendritis at the bottom of a starboard reef will rot and needs to be removed or resuspended. That same dendritis would be food for worms and other inhabitants in a DSB/Shallow sandbed.
how about glass bear bottoms and standard tank bear bottoms? as long as it's not stagnated it will not rot.

I personally believe that the engineers responsible for the next latest and greatest skimmer (I can just hear them saying "We Need More Bubbles!!! MORE BUBBLES DAMIT!") forgot their biology classes if they ever paid attention in the first place (I didn't in engineering class, so I can't blame them, ). They should have asked the question during their R&D sessions, should we really remove every last particle of organic matter down to the last part per trillion, is that biologically helpful to an aquarium?
like you said a equalibrium is best.
 

herman

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solbby said:
Herman there will never be a happy equilibrium between BB and DSB! Both require extreme different husbandry skills.

The quote "If your going to step through the door, step through deeply." comes specifically to mind.

I do realize that skimmers take out the bad as well as the good. I went BB because I am a visual person meaning I can siphon out detritus that I can see to prevent buidup. I went BB because of a crash I had blaming high nutrients lodged in my DSB. Through you guys I realize that ultimately H2S is what killed of that tank.

On the other hand I also undertand the benefits that DSB can bring. I read the arguments on both sides and happen to agree and disagree with both at the same time.

Be that as it may, I do believe at this point in time that the guys that have a DSB plumbed separately to their BB system are on to something. Would that not constitute a "happy medium"?
 

ShaunW

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Another fact to add to the pot:
Certain corals are able to complete synthesize the amino acids required for growth from light (photosynthesis) alone. Certain SPS are a perfect example. So they don't care if any bacterioplanton is present in the water column. Therefore, having a really efficient skimmer is beneficial. But if you are going to keep corals that need supplements from live feeding then having suspended food is nessesary.
 

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