DSB Diagram -- Seeking Consensus
- Thread starter Whys
- Start date
A couple of points on the narrative::
The same bacteria perform aerobicaly and anaerobicaly. There really aren't easily explainable different types so referring to the activity rather than type seems a better course.
Nitrite is not toxic to marine organisms at levels achieveable in marine tanks due to the abundance of chloride in these systems.
Sand criiters may help to alleviate anoxia in the bed but they serve an even greater function in delivering nutrients(dom, pom) to the bacteria.
The same bacteria perform aerobicaly and anaerobicaly. There really aren't easily explainable different types so referring to the activity rather than type seems a better course.
Nitrite is not toxic to marine organisms at levels achieveable in marine tanks due to the abundance of chloride in these systems.
Sand criiters may help to alleviate anoxia in the bed but they serve an even greater function in delivering nutrients(dom, pom) to the bacteria.
Man there was a lot of work going on here since Thursday. Sorry I haven't responded but it looks good to me Ryan I need to get busy and read through the previous posts but I'm pretty sure that will fit the bill. :thumbsup:
Aquarist007
New member
Just like out of a book Ryan--well done
Whys
New member
I agree, as it also avoids the need to specify anoxic. I've placed "nitrifying", "denitrifying", and "reducing" in quotes to suggest a proper name derived of their activity, rather than merely an adjective. I think speaking in terms of these three bacteria will go a long way in reducing confusion.
I'm a little confused. If this is a suggestion, then I need you to be more specific.
Thank you for saying that. I will add it to the newbie draft.
You've been a pillar of technical support in this endeavor, Tom. Your place in the credits doesn't do you full justice.
luther1200
Premium Member
I think it looks and reads well. It should be easy for almost anyone to grasp the basic concept after reading and looking at that.
Whys
New member
I don't think I want to change the wording on the bacteria "types", because I feel that would be confusing for newbies, but I can include a line in the paragraph about competing terms. How does this look?
"Also, both the nitrifying and denitrifying bacteria can be referred to as facultative. They are actually the same bacteria, functioning differently."
Also, how is this bit about the benthic?
"In addition to cleaning the sand, it is believed their gentle agitation of the bed helps deliver nutrients to the bacteria while preventing truly anoxic conditions."
"Also, both the nitrifying and denitrifying bacteria can be referred to as facultative. They are actually the same bacteria, functioning differently."
Also, how is this bit about the benthic?
"In addition to cleaning the sand, it is believed their gentle agitation of the bed helps deliver nutrients to the bacteria while preventing truly anoxic conditions."
:lol:
Still stuck on the bacteria I see. The nitrifying bacteria are strictly aerobic. They do not denitrify as they don't use carbon as an energy source. The same heterotrophs that do the initial breakdown of waste into ammonia are often facultative bacteria that can also denitrify by using the oxygen from the nitrate to oxidize carbon. In simple terms, heterotrophic bacteria can be switch hitters and live in oxygenated environments and also oxygen depleted areas under certain conditions. Autotrophic bacteria are either strictly aerobic or anaerobic. They do not cross the line.
The sand cleaning/agitation function part sounds fine.
Still stuck on the bacteria I see. The nitrifying bacteria are strictly aerobic. They do not denitrify as they don't use carbon as an energy source. The same heterotrophs that do the initial breakdown of waste into ammonia are often facultative bacteria that can also denitrify by using the oxygen from the nitrate to oxidize carbon. In simple terms, heterotrophic bacteria can be switch hitters and live in oxygenated environments and also oxygen depleted areas under certain conditions. Autotrophic bacteria are either strictly aerobic or anaerobic. They do not cross the line.
The sand cleaning/agitation function part sounds fine.
Whys
New member
Okay, I know this might be asking a lot... 
...but could WaterKeeper or tmz simply provide me with a clean short pat statement explaining the term "facultative"? 
Otherwise, I'm simply going to drop it from the text all together. Seriously guys, this isn't so amusing to me at this point. I wish to put a period on this sentence and be done with the project.
Thanks much.
...but could WaterKeeper or tmz simply provide me with a clean short pat statement explaining the term "facultative"? Otherwise, I'm simply going to drop it from the text all together. Seriously guys, this isn't so amusing to me at this point. I wish to put a period on this sentence and be done with the project.
Thanks much.
Aquarist007
New member
<a href=showthread.php?s=&postid=15161001#post15161001 target=_blank>Originally posted</a> by Whys
Okay, I know this might be asking a lot...
Otherwise, I'm simply going to drop it from the text all together. Seriously guys, this isn't so amusing to me at this point. I wish to put a period on this sentence and be done with the project.
Thanks much.
I have to admit that I have become confused again with all the similar terms being used here
I tend to keep it simple like my mind
aerobic bacteria-----nitrifyers---convert ammonia to nitrites
anerobic bacteria-----nitrifying strain--convert nitrites to nitrates
-----denitrying strain--convert nitrates to nitrogen
I am assuming WK is refering to the anerobic bacteria as faculative because they nitrify and denitrify
eddiesylas
Premium Member
There is no mention of Plennum at a glance. The only way to achieve passive water flow in the system is to provide a water void under the sand bed. I only have limited experience, but the people who do not use the plennum are always having trouble if the bed is desturbed. Also, seperating the top half from the bottom half with netting to prevent disturbance of the lower half is useful. Other than that the theory looks good, of course I will have to read more. What do you think?
Whys
New member
I've been considering what WaterKeeper said about the fifth inch of my sand bed and very low bioload. I think it is fair to say that nitrogen is not yet being produced in the lower layers. On the other hand, no visible detritus has made its way down there either. I am finally starting to notice greater activity of worms and such getting down as far the the third inch. I believe there is finally some nutrients for them to find there and so are following it as the bed develops. It wasn't my intention to keep the bioload so low for so long, but I've been battling flatworms and setting up my QT. What I'm wondering is, for the reducing bacteria to make H2S, they need both sulfate and organic carbon, correct? I understand the sulfate is present, but without transportation to the lower layers, I fail to see how either sulfate or organic carbon could feed any bacteria there. If all organic carbon is consumed before reaching the fifth inch, then does a truly anoxic layer actually matter?
Whys
New member
It's officially sticky!
Couldn't of done it without you. Thanks bunches.
http://reefcentral.com/forums/showthread.php?s=&threadid=1652103
Couldn't of done it without you. Thanks bunches.
http://reefcentral.com/forums/showthread.php?s=&threadid=1652103
Ryan,
Sulfate is omnipresent in a marine tank as SW contains, of all its dissolved salts, 7.7% sulfate by weight. Only chloride and sodium surpass it in relative abundance. Bacteria also exist at every level in even the deepest sand bed and, as we go deeper into the bed, the lower level bacteria are very good at using the slightest traces of carbon. Stuff that the aerobic heterotrophs find too difficult to hydrolyze and break down are assimilated with joy by the lower on the food chain bacteria at deeper levels. The lower level bacteria even consume the waste material excreted by their more opulent brethren. A nasty job but someone has to do it.
At the end of this ever diminishing chain of carbon consumers about the only thing left over is that goop that fuels you car and is creeping back up to $3 a gallon.
There is a tradeoff in this cycle. The upper level aerobic heterotrophs reproduce like crazy. They easily double their numbers in a few hours. The autotrophs do not have that luxury and it take them over a day to double their population. That is why it takes a week or more for ammonia to be changed to nitrate in a new tank. Obligate anaerobes take a month or so to really get into the action as they live on a minimal diet of leftovers.
Obligate anaerobes are not usually found in a properly set up DSB. The reason is that the sand shifting worms and such also brings oxygen to some degree into the bed. It may not be much but to an anaerobe it is a deadly material. By keeping the bed replenished with these sand stirrers it is unlike that even sulfate reduction will occur.
I was kidding TMZ, Tom, by mentioning a desulfinator but, in fact, that can happen in a sandbed or even mechanical denitrification system. Once nitrate is reduced and some metal oxides found in very low amounts are also relieved of their oxygen, then sulfate reduction starts to occur. It too works on specialized bacteria (there are all sorts of bacteria that can use nitrate but not so with sulfate) that reduce sulfate to hydrogen sulfide if provided with carbon to oxidize.
Back when even Paul B was a young whippersnapper.
It was thought that nitrate was harmful to marine fish and was one of the things that helped Velvet to be the plaque of the SW enthusiast. My tank back then was set up with a UGF and plastic plants and was basically a tropical fish tank using SW and with more colorful fish than anybody else had. Even with water changes my nitrate levels hovered around 120 so I needed to figure out a way to bring it down. Hence I built my own denitrifier.
A compartmented tank with nitrogen gas purging oxygen, sugar addition and some air plates to spread the fairly expensive nitrogen evenly in the reducing section. It worked but also reduced sulfate as well (back then I tested for about everything under the sun and had a lab to accomplish that feat). Faced with hydrogen sulfide coming off the unit I added a reaeration section and that solved the problem as it purged the H<sub>2</sub>S. I figured every SW enthusiast would want one but since it was almost twice the size of my tank, and used a lot of bottled nitrogen, it never made me a millionaire.
Anyway, I digress, you don't need to incorporate any of this into your model as it would frighten even the most hardened Newbie but I thought the lecture may have some value on this forum.
Good Job! :thumbsup:
Sulfate is omnipresent in a marine tank as SW contains, of all its dissolved salts, 7.7% sulfate by weight. Only chloride and sodium surpass it in relative abundance. Bacteria also exist at every level in even the deepest sand bed and, as we go deeper into the bed, the lower level bacteria are very good at using the slightest traces of carbon. Stuff that the aerobic heterotrophs find too difficult to hydrolyze and break down are assimilated with joy by the lower on the food chain bacteria at deeper levels. The lower level bacteria even consume the waste material excreted by their more opulent brethren. A nasty job but someone has to do it.
At the end of this ever diminishing chain of carbon consumers about the only thing left over is that goop that fuels you car and is creeping back up to $3 a gallon.
There is a tradeoff in this cycle. The upper level aerobic heterotrophs reproduce like crazy. They easily double their numbers in a few hours. The autotrophs do not have that luxury and it take them over a day to double their population. That is why it takes a week or more for ammonia to be changed to nitrate in a new tank. Obligate anaerobes take a month or so to really get into the action as they live on a minimal diet of leftovers.
Obligate anaerobes are not usually found in a properly set up DSB. The reason is that the sand shifting worms and such also brings oxygen to some degree into the bed. It may not be much but to an anaerobe it is a deadly material. By keeping the bed replenished with these sand stirrers it is unlike that even sulfate reduction will occur.
I was kidding TMZ, Tom, by mentioning a desulfinator but, in fact, that can happen in a sandbed or even mechanical denitrification system. Once nitrate is reduced and some metal oxides found in very low amounts are also relieved of their oxygen, then sulfate reduction starts to occur. It too works on specialized bacteria (there are all sorts of bacteria that can use nitrate but not so with sulfate) that reduce sulfate to hydrogen sulfide if provided with carbon to oxidize.
Back when even Paul B was a young whippersnapper.
It was thought that nitrate was harmful to marine fish and was one of the things that helped Velvet to be the plaque of the SW enthusiast. My tank back then was set up with a UGF and plastic plants and was basically a tropical fish tank using SW and with more colorful fish than anybody else had.
Even with water changes my nitrate levels hovered around 120 so I needed to figure out a way to bring it down. Hence I built my own denitrifier.A compartmented tank with nitrogen gas purging oxygen, sugar addition and some air plates to spread the fairly expensive nitrogen evenly in the reducing section. It worked but also reduced sulfate as well (back then I tested for about everything under the sun and had a lab to accomplish that feat). Faced with hydrogen sulfide coming off the unit I added a reaeration section and that solved the problem as it purged the H<sub>2</sub>S. I figured every SW enthusiast would want one but since it was almost twice the size of my tank, and used a lot of bottled nitrogen, it never made me a millionaire.
Anyway, I digress, you don't need to incorporate any of this into your model as it would frighten even the most hardened Newbie but I thought the lecture may have some value on this forum.
Good Job! :thumbsup:
jenglish
Marquis de Carabas
The Jaubert method using Plenum is really a different method than the more natural DSB that I believe was Whys' intent to explain. The vast majority of folks I know that run DSB do not run a Plenum. If you would like to make a plenum diagram I am sure we can debate and discuss it as well
Honestly I only ever knew one guy that ran a plenum and he couldn't tell me much about it.
jenglish
Marquis de Carabas
<a href=showthread.php?s=&postid=15163250#post15163250 target=_blank>Originally posted</a> by Whys
It's officially sticky!
Couldn't of done it without you. Thanks bunches.
http://reefcentral.com/forums/showthread.php?s=&threadid=1652103
:thumbsup:
Hi Jeremy,
Nothing wrong with Jaubert system if you do it like he described. That means having a sandbed at least 4" above the plenum. Many reefers balk at having a 6 plus inch system taking up room in the tank and cut way down on bed depth. That makes it a shallow bed with a void space under the sand and it does not work well or, more seriously, creates more problems than it solves.
Back in the mid-90's, when DSB was coming into vogue, it was found that there was little advantage in a plenum system vs. a DSB. With the added effort needed, and additional space taken up, the plenums tended to pass into history. Don't get me wrong; they still work but their value is not especially better than a properly set up DSB.
Ryan's model would probably fit a plenum system as it is not significantly different than the plenum based system.
Nothing wrong with Jaubert system if you do it like he described. That means having a sandbed at least 4" above the plenum. Many reefers balk at having a 6 plus inch system taking up room in the tank and cut way down on bed depth. That makes it a shallow bed with a void space under the sand and it does not work well or, more seriously, creates more problems than it solves.
Back in the mid-90's, when DSB was coming into vogue, it was found that there was little advantage in a plenum system vs. a DSB. With the added effort needed, and additional space taken up, the plenums tended to pass into history. Don't get me wrong; they still work but their value is not especially better than a properly set up DSB.
Ryan's model would probably fit a plenum system as it is not significantly different than the plenum based system.
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