A
Anonymous
Guest
For what its worth, I think its more worthwhile to emulate the conditions of other successful reef tanks than the conditions on a real reef.
A
Anonymous
Guest
I have a DSB and don't plan to remove it at this time because I am not having any problems. I can't see any reason to remove a DSB from a healthy tank. If algea begins to become a problem down the road, I'll yank the DSB at that time.
I don't beleive anyone is trying to say that DSB's should be yanked from existing tanks regardless of their current condition.
When setting up my 300G, I am undecided at this point. I hate the ideas of adding as much sand as would be required only to yank it later. I am leaning towards not adding one in the beginning and waiting to see how this all plays out over time. Adding a DSB later would be better than removing one.
Louey
I don't beleive anyone is trying to say that DSB's should be yanked from existing tanks regardless of their current condition.
When setting up my 300G, I am undecided at this point. I hate the ideas of adding as much sand as would be required only to yank it later. I am leaning towards not adding one in the beginning and waiting to see how this all plays out over time. Adding a DSB later would be better than removing one.
Louey
Stirring question.
It seem like if you stir the bed from the beginning, you won't let phosphates build up. The questiion becomes - how quickly do the phosphates build up? This question doesn't seem to have an answer at this time.
I stir my bed with a powerhead every 4 -6 months, and have experienced no problems - when I stir I also skim like mad, run a filter sock on the overflow, and run a canister filter with a micron cartridge.
In between stirs I also skim like mad, have good flow, and lots of macro growth in the sump.
I have the feeling that I am not letting phosphate build up in the bed to levels where they could be dangerous. I may be fooling myself, however, there are several other tanks with sandbeds, Len's for example, that are set up the same way mine is - basically, a BB set up (good skimming and flow) and between 3 and 5 inches of sand - that are doing just fine in the long term.
I am working on a way to test the amount of phosphate released during the stirring, but with a kid, time has been hard to find.
What I do think is that 'Dr' style DSB's wont work in the long term. They are like having a filter pad that you never change. At some point they fill up. If I were setting up my tank again today, I would do everything the same cept for the depth of the sand. I would go with 1 -2 inches based on the idea that a shorter sandbed would be easier to stir, and that, being smaller, it would hold less crud, and be less of a potential disaster.
Just about all of the people I have seen who blame their 'crash' on the sand were running 'Dr' stlye DSB's.
It seem like if you stir the bed from the beginning, you won't let phosphates build up. The questiion becomes - how quickly do the phosphates build up? This question doesn't seem to have an answer at this time.
I stir my bed with a powerhead every 4 -6 months, and have experienced no problems - when I stir I also skim like mad, run a filter sock on the overflow, and run a canister filter with a micron cartridge.
In between stirs I also skim like mad, have good flow, and lots of macro growth in the sump.
I have the feeling that I am not letting phosphate build up in the bed to levels where they could be dangerous. I may be fooling myself, however, there are several other tanks with sandbeds, Len's for example, that are set up the same way mine is - basically, a BB set up (good skimming and flow) and between 3 and 5 inches of sand - that are doing just fine in the long term.
I am working on a way to test the amount of phosphate released during the stirring, but with a kid, time has been hard to find.
What I do think is that 'Dr' style DSB's wont work in the long term. They are like having a filter pad that you never change. At some point they fill up. If I were setting up my tank again today, I would do everything the same cept for the depth of the sand. I would go with 1 -2 inches based on the idea that a shorter sandbed would be easier to stir, and that, being smaller, it would hold less crud, and be less of a potential disaster.
Just about all of the people I have seen who blame their 'crash' on the sand were running 'Dr' stlye DSB's.
DanConnor":rlqvtt0q said:
Agreed, to a point: success is subjective.
DanConnor":rlqvtt0q said:
Just means different phosphate levels at the bottom of the diagenesis ladder, therefore different sinked concentrations vs. time.
DanConnor":rlqvtt0q said:
Kamatani, A,; Amano, M. 1984. Phosphate and silica regeneration from fecal pellets of benthic animals collected from Tokyo Bay. BULL. JAP. SOC. SCI. FISH./NISSUISHI., vol. 50, no. 6, pp. 999-1003
Even the largest pieces of fish crap are easily broken into small enough particles to settle into a bed.
DanConnor":rlqvtt0q said:
Rightfully so. It all depends on the energy. A coastal beach shelf has high energies, lots of straining and decanting and suspension for export by currents. A low energy estuary has been receiving and sinking the import of runoff for hundreds or thousands of years with only the occasional strong storm for re-suspension. Even then, there isn’t a lot of evidence to show that any of it is exported as dissolved; just re-suspended and fluxing massive amounts of phosphate in the water column, often causing eutrophic conditions and algae blooms, which are swept away (exported) by tides.
Righty":rlqvtt0q said:
I sure ain’t got one.
Righty":rlqvtt0q said:
Ditto.
Righty":rlqvtt0q said:
[nods] It only takes a couple of centimeters to perform denitrification.
ghostofmilz":rlqvtt0q said:
If by “viable,” you mean a DSB that can be cleaned routinely to maintain a large hypoxic area for anaerobic respiration and a paucity of sunk, fluxing, dangerous porewater nutrients, I’d say yes. I’d say that’s what Righty is doing now.
Woohooo DSB Vs BB, what a battle worn arguement we have here. But check out the brain on Galleon, wow dude, quite some info you got there.
Ive got a scenario for you Galleon. Im hoping this system would make a DSB usefull, could you gimmie a run down of how you would consider it to behave.
RO/DI water all the way. So i hope we can assume that all the Phosphates being created are from two sources.
1) Wasted food (but being expirienced id imagine we could keep it minimal)
2) The Microbial and Bactereal decomposition of wastes
Main system consists of a very thin layer of sugar fine sand, with a load of Nassarus snails, Queen conch and maybee the odd tiger tail. This ensures (hopefully) that all sedimentary waste material is either directly consumed or aggitated into suspension and carried off into the sump. The basis of this sand bed is that it is aggressively turned over, hopefully negating any nutrient sinkage.
Sump contains a very large DSB of about 4-5 inches of Oolitic sand about 2-3mm dia. (i think this is ideal DSB fodder?). Due to the slow flow of the sump all the sedimentary waste will fall to the bottom where the large numbers of bethic fauna and infauna turn over the sand bed taking nutrients down to the Inoxic denitriying layer, as i beleave all DSB's intentionally do.
Now the catch with the sump is that you have a large number of macro algies and maybee a few mangroves also drawing in nutrients aiding in the denitrification process.
But wouldn't the Macro's also help in getting rid of the phosphates through synthesys? And with the constant turn over of the bed, wouldn't it manage to supply the plants consistantly, especially the mangroves that could actually draw it from the bed itself. or am i just talking crap?
Basically in summary, couldn't you have a poulation of Macro Algies in a remote situation with the sunk nutrients that could equal or exceed the creation of Phosphates from the main source? Thus ensuring that they were not trasferred back to the main system.
I like DSB's because i beleave in stability through diversity. And i dont think that LR has the capacity to Denitrify completely to a significant enough degree. Thats my reasoning for being in the DSB camp.
man do i waffle, excuse me.
Ive got a scenario for you Galleon. Im hoping this system would make a DSB usefull, could you gimmie a run down of how you would consider it to behave.
RO/DI water all the way. So i hope we can assume that all the Phosphates being created are from two sources.
1) Wasted food (but being expirienced id imagine we could keep it minimal)
2) The Microbial and Bactereal decomposition of wastes
Main system consists of a very thin layer of sugar fine sand, with a load of Nassarus snails, Queen conch and maybee the odd tiger tail. This ensures (hopefully) that all sedimentary waste material is either directly consumed or aggitated into suspension and carried off into the sump. The basis of this sand bed is that it is aggressively turned over, hopefully negating any nutrient sinkage.
Sump contains a very large DSB of about 4-5 inches of Oolitic sand about 2-3mm dia. (i think this is ideal DSB fodder?). Due to the slow flow of the sump all the sedimentary waste will fall to the bottom where the large numbers of bethic fauna and infauna turn over the sand bed taking nutrients down to the Inoxic denitriying layer, as i beleave all DSB's intentionally do.
Now the catch with the sump is that you have a large number of macro algies and maybee a few mangroves also drawing in nutrients aiding in the denitrification process.
But wouldn't the Macro's also help in getting rid of the phosphates through synthesys? And with the constant turn over of the bed, wouldn't it manage to supply the plants consistantly, especially the mangroves that could actually draw it from the bed itself. or am i just talking crap?
Basically in summary, couldn't you have a poulation of Macro Algies in a remote situation with the sunk nutrients that could equal or exceed the creation of Phosphates from the main source? Thus ensuring that they were not trasferred back to the main system.
I like DSB's because i beleave in stability through diversity. And i dont think that LR has the capacity to Denitrify completely to a significant enough degree. Thats my reasoning for being in the DSB camp.
man do i waffle, excuse me.
I believe.. there was a thread either here or on RC a while back involving Dr. Shimek's arguments that remote dsb's do nothing for denitrification in system?
Might want to look into that one.
This hobby... is so very much about experimentation. No one really knows everything about the depths of our oceans, and yes, galleon is a very intelligent guy with a lot of good ideas. However, I do not think the evidence presented calls for an alarmist position.
Anthony Calfo points out an interesting theory regarding DSB's. Take it as you will: "The reality of the matter may likely be that an incorrect application of the technology caused the rift. As aquarists, we too often have inadequate water flow, which prevents detritus and organic particulates from being properly exported by protein skimming and other filtration dynamics. In turn, excess detritus settles in pockets and migrates deep into the substrate. Furthermore, course sand and gravel is still quite popular and allows particulates to settle and accumulate rather easily."
This could explain why len (sorry you keep being the example of a successful dsb in application len) has had such wonderful success with his dsb over an extended period of time, and other aquarists have not.
And for Dan, in this same article Calfo states that denitrification is possible, though less likely in shallow sand beds.
http://www.wetwebmedia.com/deepsandbeds.htm
I read another interesting suggestion on wetwebmedia, but cannot find the article at this time. This might make the use of sandbeds in reef aquaria more viable. The suggestion was regular replacement of the sand bed. Once every so often, set aside three months, and once a month, replace a third of your substrate. Use a divider to separate the areas you are going to remove. Remove the sand slowly, down to the bottom of the tank, not in layers. Then replace with new sand and remove the divider. This allows your current fauna population to repopulate the dead sand and exports any nutrients that have accumulated in the dsb.
I will post the link here as soon as I find it, or maybe seamaiden will know which article I mean and see this post and post the link for me? *grin*
J.
Might want to look into that one.
This hobby... is so very much about experimentation. No one really knows everything about the depths of our oceans, and yes, galleon is a very intelligent guy with a lot of good ideas. However, I do not think the evidence presented calls for an alarmist position.
Anthony Calfo points out an interesting theory regarding DSB's. Take it as you will: "The reality of the matter may likely be that an incorrect application of the technology caused the rift. As aquarists, we too often have inadequate water flow, which prevents detritus and organic particulates from being properly exported by protein skimming and other filtration dynamics. In turn, excess detritus settles in pockets and migrates deep into the substrate. Furthermore, course sand and gravel is still quite popular and allows particulates to settle and accumulate rather easily."
This could explain why len (sorry you keep being the example of a successful dsb in application len) has had such wonderful success with his dsb over an extended period of time, and other aquarists have not.
And for Dan, in this same article Calfo states that denitrification is possible, though less likely in shallow sand beds.
http://www.wetwebmedia.com/deepsandbeds.htm
I read another interesting suggestion on wetwebmedia, but cannot find the article at this time. This might make the use of sandbeds in reef aquaria more viable. The suggestion was regular replacement of the sand bed. Once every so often, set aside three months, and once a month, replace a third of your substrate. Use a divider to separate the areas you are going to remove. Remove the sand slowly, down to the bottom of the tank, not in layers. Then replace with new sand and remove the divider. This allows your current fauna population to repopulate the dead sand and exports any nutrients that have accumulated in the dsb.
I will post the link here as soon as I find it, or maybe seamaiden will know which article I mean and see this post and post the link for me? *grin*
J.
Just entering the arena, and I admit that I haven't read all of the posts.
Politcally speaking, it's obvious that tanks can be kept successfully with either BB, DSB, or shallow SB. What's also apparent is that occassionally a DSB can also create problems if not properly maintained.
There are also some assumptions made in regards to DSB's.
-Having a DSB means more denitrification.
"As much as 70 to 90 percent of the overall denitrification was located in the uppermost centimeter. The remainder was found at 1-3 cm depth"
-T.K. Anderson 1984 "Diurnal Variations of Nitrogen Cycling in Coastal, Marine Sediments."
-DSB's will have a more diverse array of organisms.
I apologize for not remembering where I found this research, but you can actually achieve more diversity in a 2" sand bed with a wide range of grain sizes compared to a DSB with little or no range. Simply creating multiple environments for more kinds of microfauna.
For the record, I keep a 1.5" sand bed of various grains.
Politcally speaking, it's obvious that tanks can be kept successfully with either BB, DSB, or shallow SB. What's also apparent is that occassionally a DSB can also create problems if not properly maintained.
There are also some assumptions made in regards to DSB's.
-Having a DSB means more denitrification.
"As much as 70 to 90 percent of the overall denitrification was located in the uppermost centimeter. The remainder was found at 1-3 cm depth"
-T.K. Anderson 1984 "Diurnal Variations of Nitrogen Cycling in Coastal, Marine Sediments."
-DSB's will have a more diverse array of organisms.
I apologize for not remembering where I found this research, but you can actually achieve more diversity in a 2" sand bed with a wide range of grain sizes compared to a DSB with little or no range. Simply creating multiple environments for more kinds of microfauna.
For the record, I keep a 1.5" sand bed of various grains.
mikenegue":2x46zfse said:
It's actually a pretty advanced question that people can debate about for a long time
Here's my take: If you have a DSB, live rock isn't absolutely necessary for "biofiltration," but it is an unique habitat that will foster biodiversity (a good thing). Live rock alone definitely has the surface area to suffice for nitrification and some denitrification (IMO, DSB do the latter better), but same concept applies about limiting biodiversity because you are limiting the type of habitat in the tank if you go with live rock alone.
it seems to me that dsb's are like a nice deep carpet, that absorbs and hides most of the garbage that gets thrown into it, but you still need to vacuum it once in a while or else you'll need to replace the whole thing entirely. am I completely off base?
also, since live rock and live sand do the same thing, can we alternate between them -- maybe live rock in the fall and live sand in the spring? or maybe mix the two and have a half-depth dsb and a half-quantity of lr?
also, since live rock and live sand do the same thing, can we alternate between them -- maybe live rock in the fall and live sand in the spring? or maybe mix the two and have a half-depth dsb and a half-quantity of lr?
Well, the idea is that bacteria on the surface of the rock and sand performs nitrification, where ammonia is eventually converted to nitrate. The anaerobic insides of the rock and sand is where denitrification occurs, and the nitrate is converted to nitrogen gas.
Apparently junk can build up in the sandbed, and people are debating whether it is worth it or not, basically.
Apparently junk can build up in the sandbed, and people are debating whether it is worth it or not, basically.
Hey guys, sorry I wasn’t able to keep up with this thread today. I spent the day freezing my cajones off catching and tagging freshwater turtles in Rainbow Spring run.
Let me try to catch up…
Don’t forget, in reality there is no “wasted” food. It all makes it to the microbial/bacterial level, the bottom of diagenesis.
Plant cells leak. A lot. There is still going to phosphorous regeneration. Also, mangroves, seagrass, most algaes I’ve seen used as export in the hobby, are climax communities, that really only do well at the point phosphates are being regenerated by the sink consistently (so they only do well after the sink is full, for the most part). Right before Florida Bay’s crash, the seagrass communities had more coverage than anyone had ever seen before, but in the end, not enough of the regenerating phosphate was being exported, and you had another species succession that took advantage of the eutrophication: diatoms, cyanobacteria, etc.
The algaes that aren’t climax community organisms are adapted to the limiting amounts of phosphates produced by reefs, and are therefore not efficient competitors of algae that would take advantage of non-limiting phosphate conditions that could produced by DSB regeneration.
More tolerant/adapted always means less competitive, that’s basic niche ecology. It’s why plants like red mangroves only grow where they do. They are tolerant of the salty, water-stressed conditions, and therefore are not competitive in non-water stressed environments. They would grow fine in freshwater and nice topsoil, they just can’t compete with other plants that grow there.
Diversity can lead away from stability. A good example is increased resource pressure caused by invasive exotic species. Anyway, each little organism you put in there is more bioload. More organic mass, more bacteria food in the end, more nutrient loading, more system competition, less stability.
Sure it does, but it’s all condition dependent.
I don’t know Dan. The truth is, from the texts I’m familiar with, with the particle sizes used in most systems (2 mm and much less), there is no reason any denitrification would be done lower than 4 cm.
Hmm… in all the BB systems I’m familiar with (including the ones I curate), enough flow is implemented to keep detritus suspended for feeding corals and export via wet skimming. Unless you have a flow deficiency, no siphoning is really necessary.
Just for any who may not be familiar with the methodology I’m referring too when I say “Bare Bottom,” the idea is to have a tank with minimal detritus trapping surface. No sand, good open aquascape, enough flow to keep particles like detritus suspended, very strong skimming set to take wet foam (offgas orthophosphates and skim out detritus), and a correctly sized and run UV sterilizer to photodegrade organic phosphorous compounds and keep water-borne bacteria in check.
Let me try to catch up…
Mouse":2zbqb64j said:
Don’t forget, in reality there is no “wasted” food. It all makes it to the microbial/bacterial level, the bottom of diagenesis.
Mouse":2zbqb64j said:
Plant cells leak. A lot. There is still going to phosphorous regeneration. Also, mangroves, seagrass, most algaes I’ve seen used as export in the hobby, are climax communities, that really only do well at the point phosphates are being regenerated by the sink consistently (so they only do well after the sink is full, for the most part). Right before Florida Bay’s crash, the seagrass communities had more coverage than anyone had ever seen before, but in the end, not enough of the regenerating phosphate was being exported, and you had another species succession that took advantage of the eutrophication: diatoms, cyanobacteria, etc.
The algaes that aren’t climax community organisms are adapted to the limiting amounts of phosphates produced by reefs, and are therefore not efficient competitors of algae that would take advantage of non-limiting phosphate conditions that could produced by DSB regeneration.
More tolerant/adapted always means less competitive, that’s basic niche ecology. It’s why plants like red mangroves only grow where they do. They are tolerant of the salty, water-stressed conditions, and therefore are not competitive in non-water stressed environments. They would grow fine in freshwater and nice topsoil, they just can’t compete with other plants that grow there.
Mouse":2zbqb64j said:
Diversity can lead away from stability. A good example is increased resource pressure caused by invasive exotic species. Anyway, each little organism you put in there is more bioload. More organic mass, more bacteria food in the end, more nutrient loading, more system competition, less stability.
Mouse":2zbqb64j said:
Sure it does, but it’s all condition dependent.
DanConnor":2zbqb64j said:
I don’t know Dan. The truth is, from the texts I’m familiar with, with the particle sizes used in most systems (2 mm and much less), there is no reason any denitrification would be done lower than 4 cm.
Righty":2zbqb64j said:
Hmm… in all the BB systems I’m familiar with (including the ones I curate), enough flow is implemented to keep detritus suspended for feeding corals and export via wet skimming. Unless you have a flow deficiency, no siphoning is really necessary.
Just for any who may not be familiar with the methodology I’m referring too when I say “Bare Bottom,” the idea is to have a tank with minimal detritus trapping surface. No sand, good open aquascape, enough flow to keep particles like detritus suspended, very strong skimming set to take wet foam (offgas orthophosphates and skim out detritus), and a correctly sized and run UV sterilizer to photodegrade organic phosphorous compounds and keep water-borne bacteria in check.
okay,
there is a lot of reading and it is making my head spin.
what i am getting from some of the threads is that the dsb will collect and release phosphorous over the long haul.
my question is:
if you have a very effective and efficient fuge/algae filter...shouldn't it absorb whatever phosporous/nitrate/algae fertilizer is thrown off?
i don't have a dsb but i do have a lsb of 2 to 3 inches in both my office and home reef tanks.
i vacuum my office tank sand once a month and it is basically disgusting. the tank lloks much better after a sand cleaning and water change.
i DO NOT vacuum my home tank due to extensive rock work. i have no idea what junk is in there. what my home tank has that my office one doesnt is a really efficient fuge/algae filter.
my home tank is heavily overfed and lightly skimmed. the fuge lights are on 18 hours a day and i harvest a ton of chaeto once a week. i change water minimally and my only additive is kalk dumped (not dripped) in. tank water clarity is perfect. tank has experienced zero hair, cyano or dino outbreaks. i have about 5 hermit crabs and 10 snails in my 125g home tank.
all coral and fish are thriving and growing.
time will tell if this is an ideal set up or not.
there is a lot of reading and it is making my head spin.
what i am getting from some of the threads is that the dsb will collect and release phosphorous over the long haul.
my question is:
if you have a very effective and efficient fuge/algae filter...shouldn't it absorb whatever phosporous/nitrate/algae fertilizer is thrown off?
i don't have a dsb but i do have a lsb of 2 to 3 inches in both my office and home reef tanks.
i vacuum my office tank sand once a month and it is basically disgusting. the tank lloks much better after a sand cleaning and water change.
i DO NOT vacuum my home tank due to extensive rock work. i have no idea what junk is in there. what my home tank has that my office one doesnt is a really efficient fuge/algae filter.
my home tank is heavily overfed and lightly skimmed. the fuge lights are on 18 hours a day and i harvest a ton of chaeto once a week. i change water minimally and my only additive is kalk dumped (not dripped) in. tank water clarity is perfect. tank has experienced zero hair, cyano or dino outbreaks. i have about 5 hermit crabs and 10 snails in my 125g home tank.
all coral and fish are thriving and growing.
time will tell if this is an ideal set up or not.
If you don't have the fertilizer, you don't need the plant.
It's the ebb and flow of this diversity that's going to make it unstable.
and the rest of them that know what they're talking about have been trying to tell him he's wrong all the time. BB is extremely low maintenance and very healthy for corals that lay down calcium.
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