I've had great success with berghia nudibranchs. If the overflow is really that well invested I'd just order 6 or so and place them in there. With that much source of food they will more than likely lay eggs and rid you of your problem. They won't venture much further out that the food source if truth be told. And if they do, they will find their way back.
Are Deep Sand Beds, DSBs, dangerous to use in a marine aquarium?
- Thread starter JPMagyar
- Start date
gregrocks79
Less talk, more rock!
I had a ton in my overflow too and just used some kalk paste and injected it into them. Then sucked em out w a turkey baster. The ones in the fuge were injected w kalk paste and are now gone. Coop 1, aptasia 0 haha
Bilk
New member
Thought of suggesting that myself after seeing 100% results with a small breakout. But isolating the overflow for maybe an hour at most, to completely remove them in one shot, doesn't justify the time and expense to do it with nudis IMO. Also, at this point, the aiptasia are probably rather large in the overflow. The nudis may not be as effective on larger aiptasia and the aiptasia will still multiply while some are being consumed unless there are a lot of nudibranchs which would cost a bit.
Nuking them seems to be a more practical route. I guess they can also be physically removed using a scraper, if there's reasonable access, but the overflow still needs to be isolated from the tank and cleaned after the fact.
S2minute
New member
Are Deep Sand Beds, DSBs, dangerous to use in a marine aquarium?
First off people...Hi :wavehand: . In Jan of 2008 i setup my new system. It is a multi-tank system with a total of 400 US Gals Approx. My main DT is a 175 BF and is BARE BOTTOM. My sump is a 150 Gal Rubber maid with about 25 lbs of excess LR and is also BB. I have a 150 Gal standard connected via a Tee and serves as my cryptic zone tank.
The cryptic zone tank was the very first one to be set and before i did this i read some very interesting books. One called Sand Bed Secrets and the others the CMAT series and the captive ocean series. I hope i don't get in trouble for listing them , i'm not trying to sell or promote anything.
Anyway, i learned ALOT about DSBs and cryptic zone areas and their functions from those reads. SO, with that and reading discussions concerning DSB from years ago i did this:
I bought 1200 Lbs of South Down sand from HD. It has generally the perfect grain size and texture for infauna to thrive and it's just silica sand.
I then made 12 compartments in the standard 150 so IF i felt the need to change out the DSB i could very slowly, like 1 per month. I then labeled the compartments with the change dates after a 3 year period was reached.
Now, being what i know of the history of this system since setup i KNOW it has taken some abuse and neglect for various reasons over the first few years.
I rinsed the sand as best i could and placed in inside to a depth of approx 6". Then i took 3mm black plastic and shielded the DSB and half the tank itself from all ambient room light. The other half of the tank was exposed to ambient room light only except the DSB.
I then constructed a 5' 6" arch made of cvpvc 1/2" pipe and placed it on top of the DSB. On this i placed about 75 Lbs of LR so it never touches the DSB.
One the left top i have a return in the form of a spray pvc spray bar and the flow in is slow. On the other end i have a modified air wand about mid column using large bubbles to aid in circulation.
Then i let it set. I did NOTHING to it. I did not feed, stir or disturb the DSB in any fashion. For WEEKS while the Bac slowly populated the DSB.
Then i set up the DT Which to this date is still BB. The only big change i made was removing the elevated reef platform i built in it and used Macro rock cement to bind LR together to form many pinnacle rock formations which can easily be removed w/o disrupting the rest of the DT.
In 2012, i decided,because i knew what the original setup had been through, i thought MAYBE it be a good idea to start changing compartments. So i did change out 5 of them. I don't think i really had to however. The rest of the DSB is now nearly 7 years old. Here is what i observed over the past few years.
Scud and other infauna growth is prolific. There is absolutely no predation that i introduced to the cryptic tank and there are NO sand "sifters" or stirring animals introduced. I don't touch it, other than when i changed out some compartments.
Detritus floats down from the LR above but, NEVER accumulates. Worms and other benthic organisms pull the detritus down into the sediment and eat it. The Bac process the rest. Even the replaced compartments are now home to worms and scuds. You would be amazed at all the tunnels they create to pull in the detritus and eat it. Using a magnifying glass i could actually see them living below the sediment.
The sponge growth is also prolific. At first, i was cultivating three different species of micro algae. I've stopped a while ago but will soon restart on a smaller scale,( i was producing a total of 4 gals a week...it was kinda nuts). There is so much sponge and whatever growth on the LR of the cryptic tank, there is no longer a bare spot that i can see. I did notice however that some sponges are growing only in the 1/2 that receives no ambient room,(cryptic zone), light and others that only grow in the 1/2 that gets ambient room light,(semi-cryptic zone).
Now people, i feed the DT alot. ATM i only have one 2.5" maroon clown with it's host bubble tip. The rest of my fish had somehow fallen victim to marine Velvet and within 48 hours....QT and 93 days a fishless system fixed that
I'm concentrating on corals atm. I have a good mix of LPS and SPS under a DIY LED fixture. Last full range of tests was done on 12/23/13 and here are the results:
8PM 12/23/13 all tests using Salifert test kits except PO4
Temp: 79.4F
Sal : 1.025-26 per Refractometer
KH : 9.1
Ph : 8.05 via AC3 lab grade probe
CA : 465 Kalk/vinegar mix dosed at night per letermeter 3
Mg : 1395 maintained via water changes,(60 every 1-2 weeks) and Tech -M
K :340 i add to adjust
I2 : as iodide and iodate both undetectable i added lugols then carefully observed.
NO3 : 0.2 on low range
PO4 : 8 PPB via Hanna Phosphorus ULR 8 x 3.066 =24.528/1000=0.024PPM
Sr : I rarely check. I just add a little based on observation.
It's been going on 7 years now since this system has been up and running with the DSB installed. The Cryptic zone tank is gravity fed to the DT. I even have a 20 gal refuge with cheato in it, set up above the cryptic and is also gravity fed to the cryptic. LEDs are my sole light source now. I believe the DSB, maintained as i described above is a very positive feature to the system and honestly, i do nothing to it at all and i really feel that i did not even have to change any compartments. I'll keep it that way if i can forever or until i notice any drastic change which i don't believe likely. SO, with all that said, i give a major :thumbsup: to DSBs!
First off people...Hi :wavehand: . In Jan of 2008 i setup my new system. It is a multi-tank system with a total of 400 US Gals Approx. My main DT is a 175 BF and is BARE BOTTOM. My sump is a 150 Gal Rubber maid with about 25 lbs of excess LR and is also BB. I have a 150 Gal standard connected via a Tee and serves as my cryptic zone tank.
The cryptic zone tank was the very first one to be set and before i did this i read some very interesting books. One called Sand Bed Secrets and the others the CMAT series and the captive ocean series. I hope i don't get in trouble for listing them , i'm not trying to sell or promote anything.
Anyway, i learned ALOT about DSBs and cryptic zone areas and their functions from those reads. SO, with that and reading discussions concerning DSB from years ago i did this:
I bought 1200 Lbs of South Down sand from HD. It has generally the perfect grain size and texture for infauna to thrive and it's just silica sand.
I then made 12 compartments in the standard 150 so IF i felt the need to change out the DSB i could very slowly, like 1 per month. I then labeled the compartments with the change dates after a 3 year period was reached.
Now, being what i know of the history of this system since setup i KNOW it has taken some abuse and neglect for various reasons over the first few years.
I rinsed the sand as best i could and placed in inside to a depth of approx 6". Then i took 3mm black plastic and shielded the DSB and half the tank itself from all ambient room light. The other half of the tank was exposed to ambient room light only except the DSB.
I then constructed a 5' 6" arch made of cvpvc 1/2" pipe and placed it on top of the DSB. On this i placed about 75 Lbs of LR so it never touches the DSB.
One the left top i have a return in the form of a spray pvc spray bar and the flow in is slow. On the other end i have a modified air wand about mid column using large bubbles to aid in circulation.
Then i let it set. I did NOTHING to it. I did not feed, stir or disturb the DSB in any fashion. For WEEKS while the Bac slowly populated the DSB.
Then i set up the DT Which to this date is still BB. The only big change i made was removing the elevated reef platform i built in it and used Macro rock cement to bind LR together to form many pinnacle rock formations which can easily be removed w/o disrupting the rest of the DT.
In 2012, i decided,because i knew what the original setup had been through, i thought MAYBE it be a good idea to start changing compartments. So i did change out 5 of them. I don't think i really had to however. The rest of the DSB is now nearly 7 years old. Here is what i observed over the past few years.
Scud and other infauna growth is prolific. There is absolutely no predation that i introduced to the cryptic tank and there are NO sand "sifters" or stirring animals introduced. I don't touch it, other than when i changed out some compartments.
Detritus floats down from the LR above but, NEVER accumulates. Worms and other benthic organisms pull the detritus down into the sediment and eat it. The Bac process the rest. Even the replaced compartments are now home to worms and scuds. You would be amazed at all the tunnels they create to pull in the detritus and eat it. Using a magnifying glass i could actually see them living below the sediment.
The sponge growth is also prolific. At first, i was cultivating three different species of micro algae. I've stopped a while ago but will soon restart on a smaller scale,( i was producing a total of 4 gals a week...it was kinda nuts). There is so much sponge and whatever growth on the LR of the cryptic tank, there is no longer a bare spot that i can see. I did notice however that some sponges are growing only in the 1/2 that receives no ambient room,(cryptic zone), light and others that only grow in the 1/2 that gets ambient room light,(semi-cryptic zone).
Now people, i feed the DT alot. ATM i only have one 2.5" maroon clown with it's host bubble tip. The rest of my fish had somehow fallen victim to marine Velvet and within 48 hours....QT and 93 days a fishless system fixed that
I'm concentrating on corals atm. I have a good mix of LPS and SPS under a DIY LED fixture. Last full range of tests was done on 12/23/13 and here are the results:
8PM 12/23/13 all tests using Salifert test kits except PO4
Temp: 79.4F
Sal : 1.025-26 per Refractometer
KH : 9.1
Ph : 8.05 via AC3 lab grade probe
CA : 465 Kalk/vinegar mix dosed at night per letermeter 3
Mg : 1395 maintained via water changes,(60 every 1-2 weeks) and Tech -M
K :340 i add to adjust
I2 : as iodide and iodate both undetectable i added lugols then carefully observed.
NO3 : 0.2 on low range
PO4 : 8 PPB via Hanna Phosphorus ULR 8 x 3.066 =24.528/1000=0.024PPM
Sr : I rarely check. I just add a little based on observation.
It's been going on 7 years now since this system has been up and running with the DSB installed. The Cryptic zone tank is gravity fed to the DT. I even have a 20 gal refuge with cheato in it, set up above the cryptic and is also gravity fed to the cryptic. LEDs are my sole light source now. I believe the DSB, maintained as i described above is a very positive feature to the system and honestly, i do nothing to it at all and i really feel that i did not even have to change any compartments. I'll keep it that way if i can forever or until i notice any drastic change which i don't believe likely. SO, with all that said, i give a major :thumbsup: to DSBs!
dppitone
In Memoriam
I dig your intensity on the sand life. Our system is similar, and after years of having the sand beds and adding more sand as it becomes available from other reefers, it's absolutely overflowing with macro and micro organisms. We will never touch it, vacuum, change it out, etc.
That said, it all depends what your into. Some folks like the look of sand but want pristine-ness. Others like it be more "a la" the real reef. Whatever works for you. But if there is any danger in keeping a sand bed I'm not aware of it nor have I ever read any anecdotes of a disaster being caused by one - rather just concerns and speculation - though if it has happened to anyone that's a big misfortune and it would def be awful.
That said, it all depends what your into. Some folks like the look of sand but want pristine-ness. Others like it be more "a la" the real reef. Whatever works for you. But if there is any danger in keeping a sand bed I'm not aware of it nor have I ever read any anecdotes of a disaster being caused by one - rather just concerns and speculation - though if it has happened to anyone that's a big misfortune and it would def be awful.
JPMagyar
New member
Wow, I have been out of the conversation for quite some time, but let me stick my little toe back in at 3 AM on New Years. I promise to take a picture of a 7 year old tank with a DSB that is outstanding. In my mind this debate is ludicrous and has been from the start. There exist old beautiful reef tanks with old DSBs so Ipso Factum DSBs can not be bad in and of themselves. No matter of discussion regarding P accumulation etc can change this fact. I do not use a DSB because I prefer to control the sand bed in a shallow replacement maintenance routine rather than rely on uncertain outcomes with a DSB, but science has not studied this question and so the answer is not available yet. Why some folks here insist on arguing that the answer is knowable is truly beyond me.
I stand by my basic premise with which I started this thread:
No scientific research has been done with specific enough controls to say that a DSB is or is not harmful to maintaining a reef in a captive environment for an extended period of time. There may be reasons to believe that DSBs act as a sink for waste and those sinks may be toxic, but specific research regarding this topic does not exist whilst reefs with old DSBs DO exist so we know as a matter of pure fact that DSBs are NOT always deadly.
This is a hobby. If you want a DSB because you want to keep Garden Eels then go ahead. If you think you want to keep a reef for 30 years like Paul and you want absolute control then use some other method that allows more proven control of nutrient export.
Is it really that complicated and worthy of ongoing debate? Who benefits? Are the anti-DSB members saving tanks from crashing in the future? Is that the goal?
Just wondering.
Standby for lots of beautiful tank photos including tanks with old DSBs.
I stand by my basic premise with which I started this thread:
No scientific research has been done with specific enough controls to say that a DSB is or is not harmful to maintaining a reef in a captive environment for an extended period of time. There may be reasons to believe that DSBs act as a sink for waste and those sinks may be toxic, but specific research regarding this topic does not exist whilst reefs with old DSBs DO exist so we know as a matter of pure fact that DSBs are NOT always deadly.
This is a hobby. If you want a DSB because you want to keep Garden Eels then go ahead. If you think you want to keep a reef for 30 years like Paul and you want absolute control then use some other method that allows more proven control of nutrient export.
Is it really that complicated and worthy of ongoing debate? Who benefits? Are the anti-DSB members saving tanks from crashing in the future? Is that the goal?
Just wondering.
Standby for lots of beautiful tank photos including tanks with old DSBs.
S2minute
New member
"No scientific research has been done with specific enough controls to say that a DSB is or is not harmful to maintaining a reef in a captive environment for an extended period of time."
Perhaps your right BUT that little book i read,(Sand Bed Secrets), makes pretty good sense to me. You know what, maybe there won't be specific research or maybe there will be some day. However, maybe the research is being done right now...by the hobbyists themselves through trial and error. Maybe some of us just manage to get it right one day and there you are. Scientific research is great but, who is to say you have to be a scientist to do it?? The thought of research only able to be conducted by "scientists", i find insulting. In a way, every reef hobbyist is a scientist. Some hit it, some don't and some it just takes longer. I'm in favor of DSBs BECAUSE i did my homework, it tried...and i feel i finally got it right. Did i make mistakes along the way concerning DSBs, heck yeah i did. Did i follow what turned out to be bad advice concerning "sand beds" in the past? Definitely ...and i paid for it too. When something works you know it works. I believe all reef hobbyists are in some way scientists. Just look at the content of RC itself. If that's not specific science at work i don't know what is. I'll be looking forward to seeing to pics you promised btw
Perhaps your right BUT that little book i read,(Sand Bed Secrets), makes pretty good sense to me. You know what, maybe there won't be specific research or maybe there will be some day. However, maybe the research is being done right now...by the hobbyists themselves through trial and error. Maybe some of us just manage to get it right one day and there you are. Scientific research is great but, who is to say you have to be a scientist to do it?? The thought of research only able to be conducted by "scientists", i find insulting. In a way, every reef hobbyist is a scientist. Some hit it, some don't and some it just takes longer. I'm in favor of DSBs BECAUSE i did my homework, it tried...and i feel i finally got it right. Did i make mistakes along the way concerning DSBs, heck yeah i did. Did i follow what turned out to be bad advice concerning "sand beds" in the past? Definitely ...and i paid for it too. When something works you know it works. I believe all reef hobbyists are in some way scientists. Just look at the content of RC itself. If that's not specific science at work i don't know what is. I'll be looking forward to seeing to pics you promised btw
Just read this whole tread...Some very scientific happenings here..Curious to know how many Positives verses negatives with a deep sand bed,,usually one out weighs the other then that tells all..Like anything in life..We can try all we want to replicate mother nature but she still has plenty of secrets that we will never know..
Bilk
New member
I am in the camp that the husbandry employed, plus the methods of nutrient export, influence the success or failure of a DSB or BB tank. I do not believe one or the other or anything in between is the reason for success or failure. There are just too many examples of any of those working and being very successful.
Ding, winner...
dppitone
In Memoriam
I'm not intending to get on S2minute here, but the below quote describes "anecdotal" rather than "scientifically processed" information. What hobbyists do is create data, and they do it every day. But until the creation of the data is controlled and the results/conclusions able to be repeated according to a pre-determined "expectation," this is not the same as research in the common way the term is used.
As such, it's just the same old bu&$@&it info that circulates the hobby boards, misdirecting other hobbyists to perspectives that are "opinion" parading around as "fact," rather than actual proved results/facts in the common sense of the term. This is why I say that the marine aquarist is 20% scientist and 80% artist. Water chemistry and lighting will be and can be measured, but that's about it.
As such, it's just the same old bu&$@&it info that circulates the hobby boards, misdirecting other hobbyists to perspectives that are "opinion" parading around as "fact," rather than actual proved results/facts in the common sense of the term. This is why I say that the marine aquarist is 20% scientist and 80% artist. Water chemistry and lighting will be and can be measured, but that's about it.
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S2minute
New member
Sorry man but i just don't agree with that. While their is a lot of "opinion" out there. There is a big difference when the "facts" are based on tests and experiments by the hobbyists themselves. Not to mention through careful observation. It is what it is in a lot of cases. With most experienced hobbyists, it's their systems they see the results in, first hand. Why would any responsible reef hobbyist just throw something out there when what they refer to is based on what they eye witness first hand in their own living room or basement? That not only makes no sense at all but, that person would also have to know there are tons of other hobbyists out there that are more experienced then themselves. Why risk a foolish statement based on just opinion? When your new to the hobby, opinions like that are more expected and even accepted as just the nature of the beast. So no, i say for the "responsible" hobbyist it's more 80% scientist and 20%...opinion,(based on experience),but hey...that's just my opinion >;P
GroktheCube
New member
I tried berghias without luck. Got 18 of them, and after 3 months I saw no progress. Next, I got 2 dozen peppermints. Not all that effective, BUT they ate the remains of dead and disintegrating aips that I nukes with Joe's Juice.Well they're in there for the good eats
As for the tank denizens, I had pretty good success with berghia nudibranchs. I had maybe 6 or seven visible nasties, but if there were that many visible, I figured there were more, so I gave the nudie a try and those I was able to see are gone. I won't hesitate to use them again when the need arrises. If, if. I said if!
It's going to take a lot more than a few hours dryingThose buggers are quite resilient, you'll need to make them bone dry. Probably be easier to plug the overflow, drain it and then refill it with pure fresh water for several hours, maybe even straight up hydrogen peroxide since your going for the kill. Either way should nuke them, and without using any chemicals that will leave problematic residuals.
This is what I'll plan on doing during my next WC. Hot tap water + fresh peroxide = lots of dead aiptasia, with any luck.
S2, sounds like you have a cool setup. I'd love to have a large cryptic fuge some day.
Khemul
New member
There is a problem with the concept of a "responsible" hobbyist.
One, you have to assume the person is completely honest. This is the internet, it is extremely easy to fake data. And it doesn't even need to be intentional, ego can be a huge problem when it comes to looking at results. A DSB system crashes, is it the fault of the hobbyist with years of experience, or an inevitable result of a faulty system. Do you trust everyone to blame themselves, and not take the easy out and ignore all data that points towards anything but the DSB? Which is the second problem, accuracy. These aren't controlled systems. Even if the hobbyist isn't trying to fool themselves into thinking it wasn't their fault, they may overlook a variable. This is why science uses controls. Control allows us to minimize the variables, so the data can be accurately looked at.
One, you have to assume the person is completely honest. This is the internet, it is extremely easy to fake data. And it doesn't even need to be intentional, ego can be a huge problem when it comes to looking at results. A DSB system crashes, is it the fault of the hobbyist with years of experience, or an inevitable result of a faulty system. Do you trust everyone to blame themselves, and not take the easy out and ignore all data that points towards anything but the DSB? Which is the second problem, accuracy. These aren't controlled systems. Even if the hobbyist isn't trying to fool themselves into thinking it wasn't their fault, they may overlook a variable. This is why science uses controls. Control allows us to minimize the variables, so the data can be accurately looked at.
I got to agree with dppitone on this one. None of us in this thread have done proper experiments utilizing scientific method. Even myself, and I'm a marine biologist as well as professional aquarist. While I certainly give a lot of weight to my own observations on this subject, I still can't call them more than anecdotal observations when compared to conducting proper scientific experimentation.
Osteoclast
New member
I agree that the reef enthusiast is more artist than scientist. There are degrees of scientific discovery and proof of theories. Most scientific discovery is developed as initial experiments and viewed as preliminary data with which to build upon. Observation and careful documentation is indeed what most hobbiest's do. Observational data are important but not necessarily fact or even reproducible. This is important as a first step and is what most of us report in these forums but yet this is only preliminary to further controlled studies.
Controls require careful planning and are often incredibly complex. This allows one to control for multiple variables which can confound a result. Trials that are prospective are especially important to generate results that stand as fact. Further, power analysis, statistics, and critical review all play a key role in proving a hypothesis. Thus, an observation made by an individual is often just the first step, albeit an important one nevertheless.
Controls require careful planning and are often incredibly complex. This allows one to control for multiple variables which can confound a result. Trials that are prospective are especially important to generate results that stand as fact. Further, power analysis, statistics, and critical review all play a key role in proving a hypothesis. Thus, an observation made by an individual is often just the first step, albeit an important one nevertheless.
dppitone
In Memoriam
That's cool, reasonable folks can disagree and the vast majority of members out here are "reasonable," so no worries.
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dppitone
In Memoriam
I have a degree in Statistics, and I'll explain how statisticians approach a question - they try their damn-dist through sampling to prove the opposite of the hypothesis. And if they fail to prove the opposite, they can tend to say the hypothesis is correct.
If for example the hypothesis was 'aluminum based phosphate absorption media is harmful to soft corals," we'd do a number of samples of active and controlled experiments where we attempt to prove that aluminum isn't detrimental. Probably at least 20 active tanks and 20 control tanks. If we fail to prove this, then we can publish that in our study the hypotheses were true.
This is the bare minimum, as far as "the data" certainty is regarded. But the statistician has accountability over the data only - how to set up the sampling, collect compile data and extrapolate from it. We would need a marine biologist like Billsreef to determine how to do the substance of the tests that are in the sample.
It would work the same way if the hypotheses involved DSBs. There's no doubt enough folks of expertise on RC to get it done, if they were all together and were determined to make it happen. Yet, it's just a hobby.
If for example the hypothesis was 'aluminum based phosphate absorption media is harmful to soft corals," we'd do a number of samples of active and controlled experiments where we attempt to prove that aluminum isn't detrimental. Probably at least 20 active tanks and 20 control tanks. If we fail to prove this, then we can publish that in our study the hypotheses were true.
This is the bare minimum, as far as "the data" certainty is regarded. But the statistician has accountability over the data only - how to set up the sampling, collect compile data and extrapolate from it. We would need a marine biologist like Billsreef to determine how to do the substance of the tests that are in the sample.
It would work the same way if the hypotheses involved DSBs. There's no doubt enough folks of expertise on RC to get it done, if they were all together and were determined to make it happen. Yet, it's just a hobby.
I've used and use shallow sand, deep sand and bare bottoms. There is no scientific reason of which I am aware to favor one over the other; they all require maintenance.
It is more of an aesthetic choice.
If you like the look of sand use it and clean it periodically,replenish some with new fauna bearing sand from time to time and it should do fine for a very long time . If you want to keep critters that need deep sand like certain wrasses and anemones ,using sand beds of appropriate depth for them is a necessity
Deep sand beds lost some of their allure a a biofilter , when I realized the bacteria performing denitrification are facultative heterotrophs. They live in the presence of oxygen and when they exhaust it in a given location they turn to nitrate for it facilitating the formation of N2 gas from some of the freed up N which exits the tank. If there is left over organic material and both oxygen and oxygen sourced from nitrate are exhausted,sulfate reducing bacteria take over.
This means denitrifying bacteria can do quite well in shallow sand or even on bare surfaces . They even create hypoxic conditions in their mulm where anaerobic activity occurs;ie, using the NO3 for oxygen. So, denitrification via assimilation of dissolved nitrogen as these bacteria grow and nitrate reduction to N and N2 occurs in the top half inch or so of the bed. Not much happens down deep for denitrification since these heterotrophic bacteria need a source of oxygen organic carbon, nitrogen and phosphate to grow and not much moves down there via diffusion, a relatively weak force or even advection a bit stronger but still inadequate force. Not much organic carbon,oxygen, nitrogen or phosphate will get down there fast enough to encourage much deitrification; nor much worry about sulfate reducing bacteria taking over and producing H2S since the sufat reducers need the organics too. In fact ,ime, you can find just as much evidence(black sufides) of anoxia and sufate reduction activity in shallow beds of an inch or so asanywhere else.
Overall, a shallow bed reduces nitrate a about the same rate as a deep one since the action is near the top where the nutrients are. Thus , the choice about a sand bed is more a preference than a case of a good method vs. a bad one,imo
It is more of an aesthetic choice.
If you like the look of sand use it and clean it periodically,replenish some with new fauna bearing sand from time to time and it should do fine for a very long time . If you want to keep critters that need deep sand like certain wrasses and anemones ,using sand beds of appropriate depth for them is a necessity
Deep sand beds lost some of their allure a a biofilter , when I realized the bacteria performing denitrification are facultative heterotrophs. They live in the presence of oxygen and when they exhaust it in a given location they turn to nitrate for it facilitating the formation of N2 gas from some of the freed up N which exits the tank. If there is left over organic material and both oxygen and oxygen sourced from nitrate are exhausted,sulfate reducing bacteria take over.
This means denitrifying bacteria can do quite well in shallow sand or even on bare surfaces . They even create hypoxic conditions in their mulm where anaerobic activity occurs;ie, using the NO3 for oxygen. So, denitrification via assimilation of dissolved nitrogen as these bacteria grow and nitrate reduction to N and N2 occurs in the top half inch or so of the bed. Not much happens down deep for denitrification since these heterotrophic bacteria need a source of oxygen organic carbon, nitrogen and phosphate to grow and not much moves down there via diffusion, a relatively weak force or even advection a bit stronger but still inadequate force. Not much organic carbon,oxygen, nitrogen or phosphate will get down there fast enough to encourage much deitrification; nor much worry about sulfate reducing bacteria taking over and producing H2S since the sufat reducers need the organics too. In fact ,ime, you can find just as much evidence(black sufides) of anoxia and sufate reduction activity in shallow beds of an inch or so asanywhere else.
Overall, a shallow bed reduces nitrate a about the same rate as a deep one since the action is near the top where the nutrients are. Thus , the choice about a sand bed is more a preference than a case of a good method vs. a bad one,imo
dppitone
In Memoriam
When you say that DSBs lost some of their allure as a bio-filter, is that b/c as you pointed out, the "deep" aspect, the several bottom inches, have less of an effect for filtering compared to the space it takes up from the tank? I think that was it, I'm just not knowledgeable in chemistry, that's why I ask.
And chemistry know-how I have comes straight from Walter White.
And chemistry know-how I have comes straight from Walter White.
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