Are Deep Sand Beds, DSBs, dangerous to use in a marine aquarium?
- Thread starter JPMagyar
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sellmecorals
New member
That mix of organisms is what I want to figure out
For all the writings on sand beds no one I'm aware of has identified the right mix of organisms that will maintain a significant flow of needed nutreints into the the deep areas of a bed with any precision. On the other hand flow over shallow sand will deliver the nutrients the bacteria need and shallow sand will also provide habitat for microfuana of equal variety.
vlangel
Premium Member
I have a DSB and have always run them in my aquarium. I used play sand from Home Despot and didn't even intentionally seed it. I guess the live rock and the corals did it for me. Anyway I never do any maintenance on the sand bed at all, except 6 months ago I bought a sea cucumber. If you don't grossly overfeed and don't disturb it below the top half inch it will be a very effective nitrate export, my nitrates are always undetectable. When I broke down my last tank after 7 years the sand bed was as fresh smelling as clean ocean water. In fact I reused that sand in my current tank which is now 2 1/2 years old.
My two cents.
I moved my 240 just this week with a 6 inch sandbed that's been in this tank for close to three years. The sand was previously in my 180 for at least ten years.
When I switched tanks I used all of the sand from the 180 (unrinsed) and added more on top of it. I battled sulfur pockets for a while, but they went away after poking them gently here and there on occasion.
I'm bare bottomed right now for the first time ever in years, deciding whether or not to put sand back in. If I do, it will only be a couple/few inches.
When I tore it down to move this week, that sand was surprisingly clean with only a few grey pockets here and there. I was quite impressed.
I moved my 240 just this week with a 6 inch sandbed that's been in this tank for close to three years. The sand was previously in my 180 for at least ten years.
When I switched tanks I used all of the sand from the 180 (unrinsed) and added more on top of it. I battled sulfur pockets for a while, but they went away after poking them gently here and there on occasion.
I'm bare bottomed right now for the first time ever in years, deciding whether or not to put sand back in. If I do, it will only be a couple/few inches.
When I tore it down to move this week, that sand was surprisingly clean with only a few grey pockets here and there. I was quite impressed.
The magic mix of critters isn't really so magic. A variety of worms....spaghetti worms, hair worms, bristle worms...throw in some amphipods, nassarious snails, cerith snails, sand mopping sea cucumbers and few small hermits etc. Many of the more cryptic critters (aka the ones you find labled on a tank at the LFS) will come from introductions of LR and LS (not the bagged stuff on the LFS shelf). Getting a cupful of LS from a trusted friends healthy sand bed is a great way to get some of the critters 
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I agree sand from a trusted source with a functioning bed is a good way to replenish the critters from time to time.
I used holothuria(sea cucumbers ) as well. Some will argue they kill too many bacteria but I liked mine.My tiger tail grew to about ten inches and then split ,so I had two large ones going. nassarius snails also seemed useful, though some argue against them. Some like sand sifting gobies,: some don't. Not magical but puzzling to me from tank to tank as to what mix of critters can be sustained long term.
Sand critters can be a source of enjoyment and trying different varieties and observing them can be a source of enjoyment.
You can have a deep sand bed if you wan't it ;it can be managed ;it is not intrinsicaly dangerous as the title of the thread implies , but it's not necessary or superior for nutreint control or more" natural" as others may argue either.IMO.
I used holothuria(sea cucumbers ) as well. Some will argue they kill too many bacteria but I liked mine.My tiger tail grew to about ten inches and then split ,so I had two large ones going. nassarius snails also seemed useful, though some argue against them. Some like sand sifting gobies,: some don't. Not magical but puzzling to me from tank to tank as to what mix of critters can be sustained long term.
Sand critters can be a source of enjoyment and trying different varieties and observing them can be a source of enjoyment.
You can have a deep sand bed if you wan't it ;it can be managed ;it is not intrinsicaly dangerous as the title of the thread implies , but it's not necessary or superior for nutreint control or more" natural" as others may argue either.IMO.
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When I broke down my last tank after 7 years the sand bed was as fresh smelling as clean ocean water.
I've taken down several and the sand below an inch or so has been pristine and fresh which I take rightly or wrongly to mean mot much is happening in the deeper areas.
I've taken down several and the sand below an inch or so has been pristine and fresh which I take rightly or wrongly to mean mot much is happening in the deeper areas.
The misunderstanding probably comes from the sand surface being visibly cleaner when you have a mopping cuke. I suspect that the cukes keep the top part of the bed more productive by constantly consuming up organic accumulation on the surface of the sand grains.
Maybe, just a little process and a little bit of organics; maybe more ;don't know how enough moves down for a lot of process vis a vie the shallow areas though. sand critters could help but I'm not clear about how much. Could be but I'm skeptical in light of the bacteria's need for organic carbon, oxygen or nitrate and phosphate; their effect on N2 production will depend on how much they get . I think the upper level of the bed is much more productive.
Folks who tested beds at various depth did find no significant difference between deep and shallow in terms of nitrate reduction. One study as I recall also shows the bacteria create hypoxic areas in the mulm where anaerobic activity occurs.
Folks who tested beds at various depth did find no significant difference between deep and shallow in terms of nitrate reduction. One study as I recall also shows the bacteria create hypoxic areas in the mulm where anaerobic activity occurs.
Reefin' Dude
New member
N is easy to break down. P is not. N is not as big of a concern as P.
what exports P from a substrate? there is not a biological export mechanism for P from a substrate. if there was, we would be seeing it. we would be seeing a large amount of material moving outwards from a DSB that matches the amount of material entering it, we do not. i would like anybody to find a P cycle chart that has anything other than mechanical disruption of the substrate or tectonics as the P export mechanism.
when people say their sand is clean, what do they mean? i have never taken out a substrate that was clean. it may have been nice and white, but it is not the color of the substrate that determines if it is clean, it is all of the detritus that is around the substrate. every substrate i have removed over the years has had significant additional organic material in it that was not there when the substrate was added. all of this additional organic material represents and increase in total nutrients for the system. the P and N we can test for is only inorganic. this is a very tiny amount of the total N and P of the system. we need to look at the organically bound N and P also. just because we can not test for it, does not mean we should ignore it. the more living organisms in the system, the more nutrients needed to support them. you can not have a growing organic biomass without a growing food source to support them. where is all of this food coming from if we are "only" feeding the organisms we want to keep?
G~
what exports P from a substrate? there is not a biological export mechanism for P from a substrate. if there was, we would be seeing it. we would be seeing a large amount of material moving outwards from a DSB that matches the amount of material entering it, we do not. i would like anybody to find a P cycle chart that has anything other than mechanical disruption of the substrate or tectonics as the P export mechanism.
when people say their sand is clean, what do they mean? i have never taken out a substrate that was clean. it may have been nice and white, but it is not the color of the substrate that determines if it is clean, it is all of the detritus that is around the substrate. every substrate i have removed over the years has had significant additional organic material in it that was not there when the substrate was added. all of this additional organic material represents and increase in total nutrients for the system. the P and N we can test for is only inorganic. this is a very tiny amount of the total N and P of the system. we need to look at the organically bound N and P also. just because we can not test for it, does not mean we should ignore it. the more living organisms in the system, the more nutrients needed to support them. you can not have a growing organic biomass without a growing food source to support them. where is all of this food coming from if we are "only" feeding the organisms we want to keep?
G~
P faeries. That's why you never see them.
... or maybe the sand bed organisms that grow and breed. Larvae are both an export and a coral food source.As for plate tectonics, if that is the primary method of phosphate export in nature, I would suggest that worrying about such a trivial time scale as a few tens or hundreds of years would be silly. Plate tectonics take millions of years to cycle things. If nature can manage a few million years of phosphate accumulation in its sand beds, surely we can manage ten or twenty. No?
Reefin' Dude
New member
and that is why we have the confusion we do in this hobby. 
there are not any fairies. it sure would make things easier if there were fairies like the sand experts believed, but unfortunately there are not.
lets look at what you are saying. in order for any organisms to grow and breed it must have enough resources in order to live. if it did not, then it would not live, correct? what are these resources? how did they get there? if this organisms was really exporting P, then how is there enough P already in the substrate to support all of the organisms before it in the food chain? the fact that the organisms are there show that there is ample resources for it to survive. if we are looking for a growing population of these organisms, grow and breed, then there must be a growing amount of resources to support these organisms, correct? we are talking about the very basics of biology here, nothing difficult. no organism is greater than 100% efficient. in order for P to be exported from a marine substrate like the sand experts suggest, then there must be an organism that is producing more material as waste, then it is taking in. it just doesn't work that way.
this is not difficult stuff here, basic biology. what other hobby/livestock industry believes keeping organisms in their own waste is a good idea? a substrate is nothing but a glorified litter box, or a septic tank.
G~
there are not any fairies. it sure would make things easier if there were fairies like the sand experts believed, but unfortunately there are not.
lets look at what you are saying. in order for any organisms to grow and breed it must have enough resources in order to live. if it did not, then it would not live, correct? what are these resources? how did they get there? if this organisms was really exporting P, then how is there enough P already in the substrate to support all of the organisms before it in the food chain? the fact that the organisms are there show that there is ample resources for it to survive. if we are looking for a growing population of these organisms, grow and breed, then there must be a growing amount of resources to support these organisms, correct? we are talking about the very basics of biology here, nothing difficult. no organism is greater than 100% efficient. in order for P to be exported from a marine substrate like the sand experts suggest, then there must be an organism that is producing more material as waste, then it is taking in. it just doesn't work that way.
this is not difficult stuff here, basic biology.
what other hobby/livestock industry believes keeping organisms in their own waste is a good idea? a substrate is nothing but a glorified litter box, or a septic tank. G~
Reefers4U
Active member
The fairies are the aquarist. Export, even of P, can happen. However, it does require more than sand bed full of critters that you just sit back and take a completely hands off approach too...other than constantly throwing food (aka nutrients) into the tank. I'm not aware of any sand bed "expert" making that hands off claim. There still has to be some aquarist intervention. Occasionally vacuuming small areas of the sand bed, regular water changes, protein skimming, growing algae for export, etc. All the people I'd consider "experts" recommend such things in addition to just merely having a sand bed, because your are correct in that one can't just keep throwing food into a glass box without things ultimately accumulating.
been running 12 years + with 4" + from back of tank to like 2" towards front, the back has never been disturbed due to no real access cuz corals have encrusted all my live rock over the years, mostly acro's and montipora's, I've had to cut many acro's back over the years to create space for new goodies, I've had my bad luck as many have over the years, the sand bed over the years has depleted and I have added new sand when needed, the most important thing I have done has been taking most of my sand out of my fuge & letting macro be the major force in reducing nutrients, + I've had to run GFO constant after around 7 years & a monthly carbon change, most important is consistent water paramaters, my PO4 runs around 2 parts & NO3 40 parts using Salifert kits, I have old residents, purple & naso tangs 12 yrs, powder blue 9 years, female is 18 years along with heteractis nem same amount of time, her malr partner 11 years to name a few, my newest additions are a copperband 2 yrs + & a fathead anthias just under a year, any keeping water consistent whether your paramaters are a bit on the high side or down low just be consistent, my alk runs around 8, mag 1450, calcium 450, I have crazy good colors with my sps and other lps etc, never have carbon dosed, system is 300 gal, 75 gal sump & 75 gal frag, I run the 818 calcium reactor from GEO to keep things stable, any way just a few thoughts
No, not Fairies, faeries. Big difference.and that is why we have the confusion we do in this hobby.
there are not any fairies. it sure would make things easier if there were fairies like the sand experts believed, but unfortunately there are not.
lets look at what you are saying. in order for any organisms to grow and breed it must have enough resources in order to live. if it did not, then it would not live, correct? what are these resources? how did they get there? if this organisms was really exporting P, then how is there enough P already in the substrate to support all of the organisms before it in the food chain? the fact that the organisms are there show that there is ample resources for it to survive.
this is not difficult stuff here, basic biology.
G~
This is a chicken and egg thing. In our tanks, you need to seed a new sand bed with both food and organisms. It's not rocket science.
:eek2: You're kidding right? How can a sandbed become a cespool if there are no organics or P entering it? If there is no P entering the sand bed and thus no P source available for a population of organisms (I never said anything about growing, shrinking or staying the same) there is no problem with P accumulating either in the tank or the sandbed, thus no need for this discussion or sandbeds.
Reefin' Dude
New member
there are a few "sand experts" i can think of that made the claim that one should not touch a substrate once it has been setup, let the critters do the work. i still see this promoted on forums.
vacuuming of the substrate is the only way to remove P close to the rate that it is entering the system, or at a rate that maintains the trophic level of the system wishing to be emulated. the organic material in the substrate is the source of the inorganic P. algae, skimming, etc... are all dependent on the breakdown of these organic materials by bacteria before being able to utilize them.
what makes a substrate work is the slow migration of P downward. in order for P to migrate downward, there must be somewhere for the P to go. if a substrate is not cleaned regularly, then the P has nowhere to go and the process gets backed up. the P sink is full. other means of covering up the affects of eutrophication are needed. hence the use of GFO, algae, various carbon dolollies. they are all trying to be the next larger P sink because the biggest one in the system is full.
not trying to DSB bash here. hoping to show that we just need to clean up after our pets. that is all. the more substrate one has the longer one can wait between cleaning out the litter box. the less substrate the more often. some go without a substrate and collect it in settling areas and siphon it all out whenever doing water changes. to each their own, as long as the waste is removed at a rate that replicates the trophic level the hobbiest is trying to emulate.
G~
vacuuming of the substrate is the only way to remove P close to the rate that it is entering the system, or at a rate that maintains the trophic level of the system wishing to be emulated. the organic material in the substrate is the source of the inorganic P. algae, skimming, etc... are all dependent on the breakdown of these organic materials by bacteria before being able to utilize them.
what makes a substrate work is the slow migration of P downward. in order for P to migrate downward, there must be somewhere for the P to go. if a substrate is not cleaned regularly, then the P has nowhere to go and the process gets backed up. the P sink is full. other means of covering up the affects of eutrophication are needed. hence the use of GFO, algae, various carbon dolollies. they are all trying to be the next larger P sink because the biggest one in the system is full.
not trying to DSB bash here. hoping to show that we just need to clean up after our pets. that is all. the more substrate one has the longer one can wait between cleaning out the litter box. the less substrate the more often. some go without a substrate and collect it in settling areas and siphon it all out whenever doing water changes. to each their own, as long as the waste is removed at a rate that replicates the trophic level the hobbiest is trying to emulate.
G~
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