dadonoflaw
New member
this has probably already been covered if so could someone tell me where the link is. if not can someone illustrate the diferences and similarities between the DSB and the plenum systems as added filtration for a reef.
DSB vs. Plenum
- Thread starter dadonoflaw
- Start date
DSB's and Plenum's are not the same, if properly set-up. Grain sizes of substrate are very much different between the two.
Plenum systems do not handle as much bio load as DSB, but are less likely to suffer from Hydrogen Sulfide deposits, etc.
DSB will handle much more bio-load initially, than a plenum, but can "bite back" later on if you are overloading the system. The DSB can unfortunately appear to handle an overly large bio-load, and/or overfeeding, but as stated, will return to haunt you.
Not bashing DSB at all, I am in favor of DSB, very much so. The difference as stated still exists.
I happen to be promoting the experimental "Wasting Plenum" in advanced topics, and I would reccomend that system over a standard plenum.
It is an advanced concept however, to be sure, so read and participate in the thread if you want to consider that route.
Another option is Remote DSB, to be used on any system, and it is potentially heading in the same direction as wasting plenum.
My reccomendation would be to just go with DSB unless you like the wasting idea, and consider RDSB to go with it. Avoid Standard plenum.
> Barry
Plenum systems do not handle as much bio load as DSB, but are less likely to suffer from Hydrogen Sulfide deposits, etc.
DSB will handle much more bio-load initially, than a plenum, but can "bite back" later on if you are overloading the system. The DSB can unfortunately appear to handle an overly large bio-load, and/or overfeeding, but as stated, will return to haunt you.
Not bashing DSB at all, I am in favor of DSB, very much so. The difference as stated still exists.
I happen to be promoting the experimental "Wasting Plenum" in advanced topics, and I would reccomend that system over a standard plenum.
It is an advanced concept however, to be sure, so read and participate in the thread if you want to consider that route.
Another option is Remote DSB, to be used on any system, and it is potentially heading in the same direction as wasting plenum.
My reccomendation would be to just go with DSB unless you like the wasting idea, and consider RDSB to go with it. Avoid Standard plenum.
> Barry
Wow!!!
Barry, you were more generous than I would have been. I wouldn't have called it a "study" by any stretch of the imagination (even though it was made out to look like one). "I'm not a real study, I just play one on the Internet".
However, I agree with you. Don't pay any attention to those articles.
CaptiveReef
LED FULL SPECTRUM REEFER
Hydrogen Sulfide with DSB
Hydrogen Sulfide with DSB
but the Hydrogen Sulfide production is caused by the live rock that is stuck under the sand, and it is stated in many books,(Ref Danial Knop) to place live rock then bring sand up to the rock, I use PVC couplings to keep the rock off the bottom of the tank, and push all the sand up to the rock.
It looks like the rock is under the sand, and there is no Hydrogen Sulfide production.
The breakdown that is done in the bed is needed for the production of amino acids, which is the final end product of the waste breakdown process, (Ref Knop- Giant Clams)
The DSB is maintained by the micro fauna, which provides a job, or process called bioturbation,(Ref, Reef Notes(Julian Sprung) this is what keeps the DSB functioning properly.
Again the DSB, as the wet/dry get a bad rap for not being utilized properly, I use a huge wet/dry with a DSB and have no problems, Nitrate levels are 0.
The main issue really is how both are setup. With a wet/dry I can really stock a system and not worry about ammonia production, and with the DSB the broken down ammonia/nitrite,and the final ending product nitrate is taken care of, along with the use of carbon,phos-zorb, protein skimming, 5 gallon water change a week.
This is what I do to maintain my system.
CaptiveReef
Hydrogen Sulfide with DSB
No bashing here<a href=showthread.php?s=&postid=6594758#post6594758 target=_blank>Originally posted</a> by barryhc
DSB's and Plenum's are not the same, if properly set-up. Grain sizes of substrate are very much different between the two.
Plenum systems do not handle as much bio load as DSB, but are less likely to suffer from Hydrogen Sulfide deposits, etc.
DSB will handle much more bio-load initially, than a plenum, but can "bite back" later on if you are overloading the system. The DSB can unfortunately appear to handle an overly large bio-load, and/or overfeeding, but as stated, will return to haunt you.
Not bashing DSB at all, I am in favor of DSB, very much so. The difference as stated still exists.
I happen to be promoting the experimental "Wasting Plenum" in advanced topics, and I would reccomend that system over a standard plenum.
It is an advanced concept however, to be sure, so read and participate in the thread if you want to consider that route.
Another option is Remote DSB, to be used on any system, and it is potentially heading in the same direction as wasting plenum.
My reccomendation would be to just go with DSB unless you like the wasting idea, and consider RDSB to go with it. Avoid Standard plenum.
> Barry
but the Hydrogen Sulfide production is caused by the live rock that is stuck under the sand, and it is stated in many books,(Ref Danial Knop) to place live rock then bring sand up to the rock, I use PVC couplings to keep the rock off the bottom of the tank, and push all the sand up to the rock.It looks like the rock is under the sand, and there is no Hydrogen Sulfide production.
The breakdown that is done in the bed is needed for the production of amino acids, which is the final end product of the waste breakdown process, (Ref Knop- Giant Clams)
The DSB is maintained by the micro fauna, which provides a job, or process called bioturbation,(Ref, Reef Notes(Julian Sprung) this is what keeps the DSB functioning properly.
Again the DSB, as the wet/dry get a bad rap for not being utilized properly, I use a huge wet/dry with a DSB and have no problems, Nitrate levels are 0.
The main issue really is how both are setup. With a wet/dry I can really stock a system and not worry about ammonia production, and with the DSB the broken down ammonia/nitrite,and the final ending product nitrate is taken care of, along with the use of carbon,phos-zorb, protein skimming, 5 gallon water change a week.
This is what I do to maintain my system.
CaptiveReefRe: Hydrogen Sulfide with DSB
Re: Hydrogen Sulfide with DSB
Putting rock in the sand will certainly help promote H2S zones but it really isn't the cause. It's merely the reduction of sulphate in an anaerobic area of the bed. LR sitting in the sand can definately help lower the amount of Oxygen available so in that sense you are correct. However, having a bed that's too deep can promote them, not having good enough flow or bioturbation can promote them, etc.
Re: Hydrogen Sulfide with DSB
<a href=showthread.php?s=&postid=6608979#post6608979 target=_blank>Originally posted</a> by CaptiveReef
No bashing here
It looks like the rock is under the sand, and there is no Hydrogen Sulfide production.
Putting rock in the sand will certainly help promote H2S zones but it really isn't the cause. It's merely the reduction of sulphate in an anaerobic area of the bed. LR sitting in the sand can definately help lower the amount of Oxygen available so in that sense you are correct. However, having a bed that's too deep can promote them, not having good enough flow or bioturbation can promote them, etc.
Re: Hydrogen Sulfide with DSB
Re: Hydrogen Sulfide with DSB
I stand by my original statement, and agree with the above as well, except that Hydrogen Sulfide certainly can and will occur in a sand bed that is over loaded. I also highly reccomend keeping the rocks "off the sand bed".
I prefer keeping them actually ABOVE the bed, with at least 1" of clearance or more. This can also be done with choice selected rocks to act as "pillars". These should extend to the bottom of the tank, and are equally effective at avoiding stagnant areas, both in the sand, and at the surface of the sand.
Sand beds are supposed to be Anoxic below 1 to 2" in order to function, and they are, and they do. So why are the rocks a problem. Not because of Anoxic conditions, but because they trap organic matter at the sands surface, and down into the sand it goes, over-loading the sand in the area where the rock is, and "whalla", black-stink.
I want you to understand, I won't give DSB's a "bad rap", I'm just realistic about them. I have a small DSB now, and I'm setting up a 150 Predator tank, and a 200 gal. mixed reef, both with Guess What? Sand beds.
How can sand beds be supplemented?
Well, there is:
> RDSB the Remote DSB. It eases the load, and allows various animals to disrupt the main display sand bed to some degree, and still keep an effective nutrient control.
> Wasting Plenum. This improves nutrient processing slightly, and extends bed life, by keeping potentially harmful substances from accumulating in the sand bed. Still Experimental, but really folks, what isn't. Many people are concerned about over-oxygenating the sand bed. Yeah right, at one pint a day ?
>RUGF. The Reverse ( flow ) Under Gravel Filter was ignored as a potential solution decades ago, but that has been shown to be a fallacy. PaulB has run a RUGF for several decades, with the lowest maintainence of any known reef tank. This is with 150 gal. per hour thru the "sand-gravel" in 100(?) gal. tank.
BY THE WAY folks, that is 12,000 times the flow of the Wasting Plenum ! Over-Oxygenation ? :lol:
Now comes the "WET/DRY". I haven't investigated this one at all, but it is percieved to have problems, on a similar basis to the above mentioned options.
If the wet dry converts "most" of the ammonia to Nitrite, and then Nitrate, then what is the problem supposed to be with the sand bed having less Ammonia to process. I really never understood that one exactly.
You want to take a shot at that Curt? Captive?
> Barry :beachbum: :thumbsup: :wavehand:
Re: Hydrogen Sulfide with DSB
<a href=showthread.php?s=&postid=6608979#post6608979 target=_blank>Originally posted</a> by CaptiveReef
No bashing here
It looks like the rock is under the sand, and there is no Hydrogen Sulfide production.
I stand by my original statement, and agree with the above as well, except that Hydrogen Sulfide certainly can and will occur in a sand bed that is over loaded. I also highly reccomend keeping the rocks "off the sand bed".
I prefer keeping them actually ABOVE the bed, with at least 1" of clearance or more. This can also be done with choice selected rocks to act as "pillars". These should extend to the bottom of the tank, and are equally effective at avoiding stagnant areas, both in the sand, and at the surface of the sand.
Sand beds are supposed to be Anoxic below 1 to 2" in order to function, and they are, and they do. So why are the rocks a problem. Not because of Anoxic conditions, but because they trap organic matter at the sands surface, and down into the sand it goes, over-loading the sand in the area where the rock is, and "whalla", black-stink.
Again the DSB, as the wet/dry get a bad rap for not being utilized properly, I use a huge wet/dry with a DSB and have no problems, Nitrate levels are 0.
I want you to understand, I won't give DSB's a "bad rap", I'm just realistic about them. I have a small DSB now, and I'm setting up a 150 Predator tank, and a 200 gal. mixed reef, both with Guess What? Sand beds.
How can sand beds be supplemented?
Well, there is:
> RDSB the Remote DSB. It eases the load, and allows various animals to disrupt the main display sand bed to some degree, and still keep an effective nutrient control.
> Wasting Plenum. This improves nutrient processing slightly, and extends bed life, by keeping potentially harmful substances from accumulating in the sand bed. Still Experimental, but really folks, what isn't. Many people are concerned about over-oxygenating the sand bed. Yeah right, at one pint a day ?
>RUGF. The Reverse ( flow ) Under Gravel Filter was ignored as a potential solution decades ago, but that has been shown to be a fallacy. PaulB has run a RUGF for several decades, with the lowest maintainence of any known reef tank. This is with 150 gal. per hour thru the "sand-gravel" in 100(?) gal. tank.
BY THE WAY folks, that is 12,000 times the flow of the Wasting Plenum ! Over-Oxygenation ? :lol:
Now comes the "WET/DRY". I haven't investigated this one at all, but it is percieved to have problems, on a similar basis to the above mentioned options.
If the wet dry converts "most" of the ammonia to Nitrite, and then Nitrate, then what is the problem supposed to be with the sand bed having less Ammonia to process. I really never understood that one exactly.
You want to take a shot at that Curt? Captive?
> Barry :beachbum: :thumbsup: :wavehand:
There's NNR happening on my front glass right now and I can even look through it. It's completely invisible. It's not enough to handle the typical bioload of a reef tank but it is going on. Bacteria can create their own microenvironments whereby they can achieve low Oxygen environment simply in their biofilm. Check out this graphic.
Additionally, many people have thought that NNR occurs with no Oxygen. This is wrong. NNR occurs in low Oxygen environments by facultative anaerobes. These puppies can live in Oxygen rich environs or Oxygen poor environs or anaerobic environs. They are the ones who do the work for us and not the Obligate anaerobes.
To answer your question, let's examine how an Ecosystem sump works. (I don't use this method of filtration nor am I recommending it. At the same time, if you want to use this method, I'm not recommending against it either). It's just for an example.
Basically water runs over Bioballs to remove Ammonia and Nitrites. Then it runs over their mud which is much finer than even ESV sand or Southdown. That's where the low Oxygen environment is for NNR. This mud has a lot of Iron in it to encourage Caulerpa to grow unchecked (other than trimming) and also remove nitrates.
Additionally, many people have thought that NNR occurs with no Oxygen. This is wrong. NNR occurs in low Oxygen environments by facultative anaerobes. These puppies can live in Oxygen rich environs or Oxygen poor environs or anaerobic environs. They are the ones who do the work for us and not the Obligate anaerobes.
To answer your question, let's examine how an Ecosystem sump works. (I don't use this method of filtration nor am I recommending it. At the same time, if you want to use this method, I'm not recommending against it either). It's just for an example.
Basically water runs over Bioballs to remove Ammonia and Nitrites. Then it runs over their mud which is much finer than even ESV sand or Southdown. That's where the low Oxygen environment is for NNR. This mud has a lot of Iron in it to encourage Caulerpa to grow unchecked (other than trimming) and also remove nitrates.
Paul B
Premium Member
This is correct, but in low oxygen the aerobic bacteria will not live thus giving more room for the anaerobes. Be it as it may, there was something else that was stated also that I totally believe and it is why there are so many opinions about substrates and how they should be used. The part about using DSB's and SSb correctly. These methods will all obviousely be a benefit or a detriment depending on how they are utilized. I like RUGFs but only if you set it up a certain way. A lot of people want to use them with fine sand, big mistake, the same with DSBs. The first one I set up (in the sixtees) was with fine beach sand that I collected on NY beaches, hydrogen sulfide city. I know hydrogen sulfide well because I spend many hours on muddy beaches collecting amphipods and whatnot at low tide. About half the rocks I lift have no life because of hydrogen sulfide, you can tell immediately by the black color and smell. You don't get this on the same beach where there is courser sand instead of mud.
The most efficient filtering method is a wet dry. For a FO it is the way to go but they work too well for our needs and supply too much oxygen so no anerobes can live.
All of these systems work very well sometimes and they all can crash if used incorrectly. I am sure my tank would have crashed years ago if I did not have screens on my RUGF and just let it fill up with detritus, I am also sure that a DSB will crash very shortly if too fine a sand is used. On a microspopic level a few microns can mean success or failure. This is something that we can't always see with our eyes but it is the reason why so many people have so many problems. When we are dealing with microbes, fine details are important.
Paul
Point well taken. I know you've read some of my posts and know that I advocate some sand grains that are larger than some of the experts recommend. I also recommend higher flow than most people recommend to keep the sandbed clean of detritus as much as possible.
I personally don't like the way DSB's are sold to hobbiests these days. I have had them before and they are much more complex than throwing some sand in a tank, throw in some worms, and you are good to go. Now you can do whatever you want and you will never have problems because your sandbed will take care of it. :rolleye1:
I personally don't like the way DSB's are sold to hobbiests these days. I have had them before and they are much more complex than throwing some sand in a tank, throw in some worms, and you are good to go. Now you can do whatever you want and you will never have problems because your sandbed will take care of it. :rolleye1:
Point exceedingly well taken !
I have much interest in setting up my 150 gal. predator tank with RUGF. Not FO though, to include some softies and LPS. Very similar to your tank Paul.
The fine details are important. How fine is fine? I went round and round with a "Shimek" disciple recently, who insisted that if I used even a portion of the grains as coarse as 1.5mm, I would be setting up a "kill zone" at the surface of the bed.
Same source insisted that I needed "flour" ( or mud ) sized particles included in the "mix". I tend to disagree strongly, but can't come up with "evidence", other than "anecdotal", to support my position. Flour, mud, and "super fine", sound like PLUG-PLUG-PLUG, and Hydrogen Sulfide to me.
Back to particle sizes, and composition. Paul, please help us out here. Albeit, you are not a bonafied "expert", I will take your experience and anecdotal evidence, gladly, as a valid source.
Araganite "dissolves" at low pH, and is considered to "buffer" our alkalinity and Calcium, while I believe, that it simeltaneously releases Phophate that was included in its formation, and then remineralizes near the surface of the bed, as it encounters the 8.2 ph water at the surface of the bed, promoting clumping, stagnation and general "yuckiness". The phosphate probably diffuses right on up into the water column.
You use dolomite "primarily" in your system, which does not suffer from this problem so much, I presume. Silica sand or fine Quartz have been looking like good alternatives to me as well, considering the non-dissolving, and therefore "non-releasing" charachteristics of these potential substrates.
You have told us that you have added various sands and even muds to your system, over the long term. So . . . .
Can you tell us ( or me ) how you would reccomend to properly set-up a RUGF system ?
How fine is fine ? I don't know whether you, or others are intimately familiar with substrate "sizes". Here are a few examples:
>> Oolitic sand > generally specified as .2 to 1.2 mm . The larger 1.2mm being what I see going into concrete mixes and horseshoe pits. Carib Sea has a version that is .1 to 1.1mm .
>> South Down > Rather similar to "Oolitic", but goes down to "flour" sized particles ( .035mm ), which I personally am not in favor of.
>> "Mud" ( or flour sized ) My wifes white flour in the kitchen measures .035mm or .0014" . That is 1/3 the thickness of common human hair.
>> Sugar Sized > Commonly considered analogous to "Oolitic" sand. I get .3mm, or .012" . 3 1/2 times larger than human hair.
We could take these values "with a grain of salt", but I haven't measured that yet. :lol: ( COMING SOON ! ! )
So Paul, here is the question , If you were to set up a tank today, to approximate the general conditions that have served you so well, all this time, what composition, grain size(s), and depth of bed would you start with to go along with the RUGF filter?
I assume you would reccomend the Algae Tray as well ( I like that one ), how about skimming, and what else should we consider ?
Thanks a bunch ! > Barry :beachbum: :thumbsup:
ooPS: dadonoflaw, I t may appear that "we" have hijacked your thread, but if this isn't Reef Keeping education, I don't know what is !
Paul B
Premium Member
Barry for the RUGF that I have I got out my ruller for this scientific measurement. As you know that gravel has been in my tank since it was a brackish tank in the sixtees so a lot of the grains I am sure fractured but it seems they range from 1/8th inch to 1/16", Like I said, there is a lot of smaller sand grains in there due to adding material and the boring of the animals themselves on the rock. I think crushed coral may be a little too large.
I have 3 UG filter plates in a 6' long tank. All three tubes were bent where they emerge from the gravel and travel at the bottom of the tank to go up at one side at the rear. They enter the bottom of a plastic container about an inch above the water which is actually an old hang on filter. The water enters the container from a submerged powerhead which pumps 450 gal/hr.
The powerhead is upside down near the surface with a sponge on the intake. I did this so I can just remove the sponge for cleaning without hardly getting my hands wet.
You will not get nitrate reduction until some detritus forms in between the grains and slightly reduces the oxygen. You know about the skimmer and algae trough.
Good luck.
Paul
The green thing next to the rusty fan is the container where the tubes enter. (give me a break, it's old)
You can see the sponge at the surface.
I have 3 UG filter plates in a 6' long tank. All three tubes were bent where they emerge from the gravel and travel at the bottom of the tank to go up at one side at the rear. They enter the bottom of a plastic container about an inch above the water which is actually an old hang on filter. The water enters the container from a submerged powerhead which pumps 450 gal/hr.
The powerhead is upside down near the surface with a sponge on the intake. I did this so I can just remove the sponge for cleaning without hardly getting my hands wet.
You will not get nitrate reduction until some detritus forms in between the grains and slightly reduces the oxygen. You know about the skimmer and algae trough.
Good luck.
Paul
The green thing next to the rusty fan is the container where the tubes enter. (give me a break, it's old)
You can see the sponge at the surface.
JerseyReef
Premium Member
I completely agree. My DSB has been up and running in two different systems since late '98. Why? the initial construction of the sand is different than what Dr. Ron was using around '00. Mine is mix of ESV (before southdown), small crushed coral and a larger fine grade sand (both from Carbsea). Mixture is as follows if memory serves me correctly:
ESV 90%
small crushed coral 3%
larger fine grade sand 7%
Now, I have added to the system over time when needed (sand still dissolves over time). Usually Southdown is added along with a small amount of small CC. I've recharged the system once in that time frame (new fauna in '01). However, I used a long setup time before anything was added to the tank. I have to look up my notes, but 6 months is the norm before I add anything to a system (fish or coral).
You are right, the DSB's sold today are just being setup incorrectly and not being built as intended, IMO.
Nice post Mike.
Come visit here.
http://reefcentral.com/forums/showthread.php?s=&postid=6634114#post6634114
> Barry
Come visit here.
http://reefcentral.com/forums/showthread.php?s=&postid=6634114#post6634114
> Barry
CaptiveReef
LED FULL SPECTRUM REEFER
Re: Re: Hydrogen Sulfide with DSB
Re: Re: Hydrogen Sulfide with DSB
The sandbed is limited to the amount of Ammonia breakdown by the available surface area of the sandbed, and also the depth of the sand bed also plays a role in the beds ability to breakdown Ammonia. Most beds have oxygen in the upper levels and as you go deeper you have less oxygen.
As far as wet/dry's go, they are the best way to handle ammonia and nitrite, and when used with a DSB you are able to keep nitrates at around 0 ppm, and maintain a fully stocked tank.
How's that Barry? :dance: :wavehand:
CaptiveReef
Re: Re: Hydrogen Sulfide with DSB
How can a sand bed have less Ammonia to process?, the amount of Ammonia production is based on the amount of bio load in the tank.
The sandbed is limited to the amount of Ammonia breakdown by the available surface area of the sandbed, and also the depth of the sand bed also plays a role in the beds ability to breakdown Ammonia. Most beds have oxygen in the upper levels and as you go deeper you have less oxygen.
As far as wet/dry's go, they are the best way to handle ammonia and nitrite, and when used with a DSB you are able to keep nitrates at around 0 ppm, and maintain a fully stocked tank.
How's that Barry?
:dance: :wavehand: CaptiveReef
Re: Re: Re: Hydrogen Sulfide with DSB
Re: Re: Re: Hydrogen Sulfide with DSB
If you add a Wet/dry to an existing sand bed system, and the wet/dry processes Ammonia into Nitrite and then into Nitrate, then there is less Ammonia for the sand bed itself to deal with, No ?
X = Total Ammonia, derived from bio-load
Y = Ammonia processed by Wet/dry
Z = Ammonia processed by Sand Bed
So X - Y = Z . . . Right ?
Z < X . . . . Right ?
So a Sand bed has less Ammonia to process IF, A wet/dry is used in conjunction.
Back to the original question. Why has this been considered by people, in the past, to be a problem ? ? :hammer:
> Barry :beachbum: :thumbsup: :wavehand:
Re: Re: Re: Hydrogen Sulfide with DSB
<a href=showthread.php?s=&postid=6635865#post6635865 target=_blank>Originally posted</a> by CaptiveReef
How can a sand bed have less Ammonia to process?, the amount of Ammonia production is based on the amount of bio load in the tank.
The sandbed is limited to the amount of Ammonia breakdown by the available surface area of the sandbed, and also the depth of the sand bed also plays a role in the beds ability to breakdown Ammonia. Most beds have oxygen in the upper levels and as you go deeper you have less oxygen.
As far as wet/dry's go, they are the best way to handle ammonia and nitrite, and when used with a DSB you are able to keep nitrates at around 0 ppm, and maintain a fully stocked tank.
How's that Barry?
CaptiveReef
If you add a Wet/dry to an existing sand bed system, and the wet/dry processes Ammonia into Nitrite and then into Nitrate, then there is less Ammonia for the sand bed itself to deal with, No ?
X = Total Ammonia, derived from bio-load
Y = Ammonia processed by Wet/dry
Z = Ammonia processed by Sand Bed
So X - Y = Z . . . Right ?
Z < X . . . . Right ?
So a Sand bed has less Ammonia to process IF, A wet/dry is used in conjunction.
Back to the original question. Why has this been considered by people, in the past, to be a problem ? ? :hammer:
> Barry :beachbum: :thumbsup: :wavehand:
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