DSB's

[MikeS]

Hi all

I have been seeing a number of posts in different forums about people who have had DSB's "fail" on them...

What I'd like to know is how many here use DSB's, (in your main tank, sump or both) how long have you had it, and have you experienced any problems with it?

If you don't have a DSB, what are the reasons you don't use one?

I have used a DSB in my tank for over 3 years now, with no problems. The tank has been moved twice with the DSB intact, and it still functions well.

Your opinions and input are valued here....


Mike

[cich1]

i don't have a DSB the reason i didn't go that route was because my tanks only a 29g and i didn't want to fill it up with sand, when i go bigger in the future i probably will go DSB

[MikeS]

chic1...what do you do for nitrate reduction in the meantime?

Mike

[cich1]

my tanks only been running for 2 months, i just started adding snails saturday so nitrates haven't been a problem yet, i played around with a refuge in my sump but the flow through there is to much so now i'm looking at hob refuges until i get it worked out i'll have to count on water chages to keep nitrates down, i'm always willing to listen to suggestions though

[MikeS]

if you have a sump, I'd put a DSB and some macros in there...

Mike

[cich1]

i tried that but i'm running about 700 gph through a 10g sump and it just blew the macros apart, i have another spare 10g tank i have an idea for a new design i'm going to give a try

[MikeS]

yeah, that could be a problem :D ...DSB's don't like to be disturbed too much...

How large is your sump? I've seen baffled sumps with high flow rates and DSB's....

Mike

[Zack]

I run a 1.5-2" sand bed in the main tankf ro about 3 years and have no issues. In my old refugium i had a 3" sand bed for about a year and again no issues. With my new large refugium, i have about a 4" sand bed which has been running fine for 3 months.

Many MANY people in my local reef club run with out deep sand bed, in fact, their is a T-shirt idea going around that says, " Friends don't let friends do DSB" :lol:

[MikeS]

I run a 1.5-2" sand bed in the main tankf ro about 3 years and have no issues. In my old refugium i had a 3" sand bed for about a year and again no issues. With my new large refugium, i have about a 4" sand bed which has been running fine for 3 months.

To get the denitrating benefits of a DSB it needs to be at least 4" deep.


Many MANY people in my local reef club run with out deep sand bed, in fact, their is a T-shirt idea going around that says, " Friends don't let friends do DSB" :lol:

Can you tell me why your reef club against DSB's? I have some opinions on why some DSB's fail, but I'm still a firm believer in them, if they are properly maintained.

[Zack]

I personally, amd not looking for the benefits of it in my main tank, just a more natral look.

As for some info on the dsb, i grabbed this from Mike (mojo). http://mojoreefs.homestead.com/files/newsite/index1.html

The DSB. A dsb is set up as a denitrifier, it is based on bacteria not bugs, the bugs stir the bed but the bacteria does the work. From nitrification (ammonia to nitrite to nitrate) in the areboic zone (about 1 inch level. Then denitrification (nitrate to nitrogen gas) in the anoxic zone (transistion zone between areobic and anerobic) . the anoxic zone is about a 1/2 deep and is just below the areobic zone. OK from here on down is the anerobic zone (no oxygen) and contains only bacteria that reduce sufide, methagenes and so on. Thier biproducts (waste) is toxic and does nothing for the system, could actually kill the tank. so that is how it is made up. So if you have a 6 inch bed 1 1/2 to 2 inches do you SOME good the rest is dangerious. So bottom line here is if it isnt nitrogenious waste it sinks, if it sinks and you tank has a botton the bed will fill over time and become all anerobic.
Ok another problem with sand substarights (biggest problem for us) is Phosphates. We can only test for inorganic phosphate which is tiny in percentage to the organic phosphate in our tank. Now argonite sand is a super sponge of phosphate. With critter activity the phosphate laidened sand is dropped down to the lower ph waters of the dsb, this releases the phosphates and it is taken up by algaes (blooms of cyano and hair and so on). the algae grow and uses up the phosphate, then it begins to die off as the nutrient is used up, this decaying vegitaion creates a bloom of bacteria that begins to reduce it. As it reduces the algae in binds the phosphate to itself. Then the food runs out for the bacteria, and it begins to die off, and thus releases the phosphate back into the water, and thalgae bloom begins all over again. A continious cycle. Now by feeding our tanks and adding additives we continue to add phosphate to the system. so the blooms (bacterial and algae) become larger and more often. with the large bacteriaal blooms the respiration of o2 is huge and will in itself will create anerobic zones and thus greatly age the bed.
So the good about a DSb is that it process nitrogenious waste.The bad is that is all that it does so everything that is not nitrogen based sinks and fills the bed. the phosphate problem is huge and thats why you always here about folks with the algae blooms.
Min we are always trying to export waste from our tank but with the sand bed we store it...doesnt make sence to me. If you setup a simple maintence schedule of vacuuming out a thin substraight or Bare bottom the waste is gone and does not have to be processed...nada...zippo...gone.
Min if you want my opinion, get rid of the sand and replace it with a bit of maintenance and you dont have to deal with it later. Remember you have LR in the tank and it does the exact same thing but it doesnt sink. it actually sheds it. If you dont like the look of bare bottom the put a little bit of CC down to cover the exposed areas. 2 inches is going to do the same thing with phosphates and will sink what it doesnt process, remote beds will starve and die out infuana wise, thus making it useless. Unless you feed it , which kinda defeates the porpose.

[Condiman]

4" sandbed in my main tank and 5" sandbed in my sump. I have notice a drastic drop in my nitrates and also my algae problem went away completly.

[MikeS]

I agree Zack, that if you don't want to use a DSB for denitratfication, and you have another suitable means to accomplish this that keeps nitrates low enough for a reef tank, then they are not a necessity.

I read your friend's text....He has some points in there, but I think most of them are overstated or not the result of the DSB itself. ( I started this thread to get some freindly debate and viewpoints :D )

His first point deals with biproducts of the DSB, mainly hydrogen sulfide. His statements are factual, but the risk is overstated IMO. I base this on two things....One, I've completely drained and moved my tank twice with the DSB intact. The DSB was definately disturbed, and you could smell the unmistakeable stench of rotten eggs (hyrdogen sulfide). This was no doubt released into the newly moved tank, I could still smell it for a few days after the move. I however, suffered abolutely no loss of livestock, the smell disappeared, and the DSB quickly returned to its denitrating ability.
Two, I live in Wyoming, home of hotsprings and oil wells, I smell hydrogen sulfide regularly. It is dectecable by the human nose in parts per billion. A lethal dose is much higher than this. I also remember this rotten egg smell when cleaning out canister and HOB filters on my FO tanks, with no DSB. These wastes also occur in real reefs (ever smelled low tide? :? ) yet the reef seems to be able to deal with them....IMO a well maintained DSB does not produce these wastes in levels high enough to be lethal to your livestock.

His second argument has to do with phosphates. I will concede that a DSB may provide a bit more surface area for pecipitated phosphates to accumulate. However I think it is important to remember what the #1 cause for phospahte introduction into the reef tank is...they hobbyist. Whether it be from feeding, water, cleaning the house, ( I have even read that scented candles burning in the house can elevate phosphate and other pollutant levels in the tank) we indroduce phosphates into the reef. The DSB itself does not produce them. The phosphate will accumulate in the tank no matter what, DSB or no DSB. IMO I seriously doubt the DSB makes phosphates any greater or more significant of a problem than they would be without one.

The DSB IMO has many benefits to the reef, but it is essentially a living entity and must be treated as such. If properly cared for in a well maintained reef IMO it is still the best method available for nitrate reduction.

I think if I had a local reef club, our shirts might say " Friends don't let friends buy the bad myths of DSB's" :D

thanks for the article Zack...I hope we get lots of good discussion on this topic..., I'm old school, but I'm ALWAYS looking for new viewpoints and opinions, that's the only way we grow and learn in this hobby!

Mike

[Charles Poole]

I feel that a DSB wouold be a significant advantage to any marine tank. Providing that it is trully functional.

Dr. Shimek makes it pretty clear that without a seeded stock of actual sand bed micro-fauna, then we are playing Russian Roulette with DSB's

I am actually in the process of re-establishing a DSB in my 125 gallon. I am setting up zones of different gravel sizes, and noting the inhabitants I find there. I will write an article about it when I am finshed. :)

Live Sand is not enough. It needs to be from the reef "alive". Many stores sell Live Sand that is not much more than Nitrogen processing sand. Has the bacteria capable of processing Ammonia and Nitrite, and maybe even nitrate. But no real activity is occuring otherwise.

Ask the stores employees where the get there Live Sand from. Bet you get an "I don't know", or a "We just dump some sand in the tank every couple months or so". So buyer beware... :)

Anyways, I am a pro-DSB guy myself...

[MikeS]

Chuck....do you think that "Live Sand" is a must initally for a DSB? I've read Dr. Rons article also.

I never added "live sand" to my tank, only dry aragonite, yet my DSB has kept my nitrate levels undetectable for over 3 years...

Mike

[icereefer]

I never used LS either the pre bagged type.
but I have noticed if my critter colony gets low it plays a big factor on my DSB.

[cich1]

has anyone used the critter starter kits or sand bed recharge kits they sell online? if so is it a worth while investment?

[icereefer]

I guess no I haven't, but I know if you can find cheato macro I've found most of the time,it"s full of mini brittle stars, pods, bristle worms, snails, and many other critters.

[mojoreef]

Hello folks, Zack asked me if I could drop in to your board and maybe explain my comments in regards to DSB's and my statements about it. SO first off Howdy. lol
Just to kind of preface what I was talking about, I dont really think DSB's are a bad method of filtration, it just have limitations and guidelines that need to be followed if a person is going to have a chance at long term success. That and in most cases DSB filtration has been truly oversold.

I wanted to address a few statements on the thread if that is alright. On the sulfides, they are not really a toxic problem as pointed out by Mike, unless they are stirred up while the inhabitants are in the tank. What a sulfide zone does tell you is the location of your anoxic zone. Sulfide reducing bacteria are not faculative, they only live in that type of zone, So if you have a sulfide zone, you can assume that denitrification and nitrification are only working in the areas above, and that all areas below do not pertain.
Mike on the Phosphates you are missing some key points my friend. the sand that you put into your sand beds is already saturated with Inorganic P. the saturation occurs natural in the wild prior to the sand even being harvested or mined. In the case of mined sand it is even worse as it contains nutrients absorbed through runoff. Alot of the up front P is truly added to your tank via feeding, additives and so on and as you mentioned limiting is the best medicine for that. As a DSB matures it develops zones (anaerobic, aerobic and i some cases anoxic) In the lower zones through the actions of bacterial enzymes and natural lower ph (lack of oxygen) the sand will begin to melt, I believe most backers call this the dsb's buffering system. with this melting calcium and carbonate are not the only thing to be released, All things once bound in the sand once again become soluble including P. this leeching of P is a constant cycle in the life of a dsb system. Even according to the self proclaimed DSB experts a dsb has no method for dealing with P unless the harvesting of algae from it is considered.
One last one, hehehe. With the statement of a DSB being the best method of nitrate reduction. I just wanted you to maybe take a look at it from a different angle. What if you skipped the whole concept of the nitrogen cycle and just removed the waste/detritus prior to it rotting??? wouldn't that be the truly best way of avoiding it???

just a thought and sorry for the rambling post


Mike

[MikeS]

Hello folks, Zack asked me if I could drop in to your board and maybe explain my comments in regards to DSB's and my statements about it. SO first off Howdy. lol

Hi mojo...welcome to the forum! I appreciate your weighing in on this topic....

Just to kind of preface what I was talking about, I dont really think DSB's are a bad method of filtration, it just have limitations and guidelines that need to be followed if a person is going to have a chance at long term success. That and in most cases DSB filtration has been truly oversold.

I'll agree, a DSB must be properly set up and maintained, and it is not a magic cure all solution like I think many reefers expect. IMO it works best in concert with other methods of nutrient export, like macroalgae, skimmers, and water changes.

Mike on the Phosphates you are missing some key points my friend. the sand that you put into your sand beds is already saturated with Inorganic P. the saturation occurs natural in the wild prior to the sand even being harvested or mined. In the case of mined sand it is even worse as it contains nutrients absorbed through runoff.

If this is the case, than why don't tanks with DSB's have constant, cronic cyano/algae problems? My cyano outbreaks are few and far between, and are usually quite mild. I have algae outbreaks from time to time, but I can almost always attribute them to something I did (or didn't do) to the tank myself.

Alot of the up front P is truly added to your tank via feeding, additives and so on and as you mentioned limiting is the best medicine for that. As a DSB matures it develops zones (anaerobic, aerobic and i some cases anoxic) In the lower zones through the actions of bacterial enzymes and natural lower ph (lack of oxygen) the sand will begin to melt, I believe most backers call this the dsb's buffering system. with this melting calcium and carbonate are not the only thing to be released, All things once bound in the sand once again become soluble including P. this leeching of P is a constant cycle in the life of a dsb system. Even according to the self proclaimed DSB experts a dsb has no method for dealing with P unless the harvesting of algae from it is considered.

That makes good sense, I have heard that before. I'd say however, observing my 3+ year old sand bed that such leeching is probably minor, and easily dealt with by a good regular water change schedule, and perhaps some macro algae, either in a sump or in the main tank.


One last one, hehehe. With the statement of a DSB being the best method of nitrate reduction. I just wanted you to maybe take a look at it from a different angle. What if you skipped the whole concept of the nitrogen cycle and just removed the waste/detritus prior to it rotting??? wouldn't that be the truly best way of avoiding it???

Point taken, however, I'd say it's near impossible to remove all the waste/detritus prior to rotting. The nitrogen cycle is going to exist no matter what....I guess it is a question of to what degree. I personally like a good strong biological filtration ability in my tank. A DSB works best as Chuck stated with the proper fauna, scavengers, and detrivoures present in the tank, to reduce as much of the waste as possible. That is the key IMO to success with a DSB, don't overload it!

just a thought and sorry for the rambling post
Mike

Not rambling at all, thanks for the response and opinions, that's why I strated this thread!

Mike

[mojoreef]

Thanks for the warm welcome Mike, I felt a little ackward, in the above being my first post here. Its nice to debate such issues without emotion.

If this is the case, than why don't tanks with DSB's have constant, cronic cyano/algae problems? My cyano outbreaks are few and far between, and are usually quite mild. I have algae outbreaks from time to time, but I can almost always attribute them to something I did (or didn't do) to the tank myself.

Mike if you monitor most of the BB's out thier most do. Again it depends on you husbandry. P will get locked into a Algae/bacterial cycle and will flux pending on input. What usually helps folks is if they stir the top layer and remove the detritus. It kind of give the bed a bit of a break and exports the bacteria, which will break the cycle.

That makes good sense, I have heard that before. I'd say however, observing my 3+ year old sand bed that such leeching is probably minor, and easily dealt with by a good regular water change schedule, and perhaps some macro algae, either in a sump or in the main tank.

In order to export it my friend your going to need to get it where it lives, in the dsb. You have to remember to that P is in high demand all over the tank. It will percipate calcium, It will inhibit calcification, and bind with most other elements in NSW. it also come it alot of forms (ie particulate, soluable, Inorganic organic, ortho and so on). P is truly one of the most important things in a reef tank to keep watch for. most folks dont.

Point taken, however, I'd say it's near impossible to remove all the waste/detritus prior to rotting. The nitrogen cycle is going to exist no matter what....I guess it is a question of to what degree. I personally like a good strong biological filtration ability in my tank. A DSB works best as Chuck stated with the proper fauna, scavengers, and detrivoures present in the tank, to reduce as much of the waste as possible. That is the key IMO to success with a DSB, don't overload it!
And here is where the two methodologies part company. You can biol it down to two choices at this point. One hand (dsb) takes waste/detritus and so on and puts it into a complex biochemical cycle for it to be exported by means of skimming, water changes, algal harvesting. and on the other hand one removes the waste/detritus and so on prior to decomposing and skips straight to export through the same basic methods. Also dont forget that with either system we all tend to have LR in our tanks, which is a solid source of denitrification unto itself.

take care and thanks for the good conversation


Mike

[MikeS]

Thanks for the warm welcome Mike, I felt a little ackward, in the above being my first post here. Its nice to debate such issues without emotion.

Absouletly :-D
No need to feel awkward at all, I posted this thread to get different viewpoints. I always enjoy reading others thoughts on controversial subjects. I find the best way to grow and learn as a reefkeeper is to challenge my own convictions from time to time :-D I hope you will become an active member here!


Mike if you monitor most of the BB's out thier most do. Again it depends on you husbandry. P will get locked into a Algae/bacterial cycle and will flux pending on input. What usually helps folks is if they stir the top layer and remove the detritus. It kind of give the bed a bit of a break and exports the bacteria, which will break the cycle.

I have seen more posts than I could possibly count on cynao/algae outbreaks, but I honsetly don't believe I have ever noticed posts on the problem in tanks with DSB's in any greater number than tanks without them. I think this has more to do with maintenance practices, feeding, experience of the reefkeeper, ect. than the fact that a DSB is used or not used.

The issue of phosphates and DSB's is definately a controversial one. I have read many experts opinions, some say phosphates in DSB's is a problem, and others, like Dr. Ron Shimek, say that DSB's do not hold or accumulate phosphates. I suppose it all depends on who you beleive. I personally put a lot of faith in Dr. Ron's words, he seems to me to be the foremost advocate of DSB usage, and has done a great deal of research on the subject. Also, the fact that in the last 3+ years I've had a DSB and have experienced far fewer cyano/algae outbreaks than in any other tank I have ever maintained lead me to believe that DSB's do not signifiacantly contribute to a phosphate problem. I'm sure we could bat this topic back and forth indefinately :-D


In order to export it my friend your going to need to get it where it lives, in the dsb. You have to remember to that P is in high demand all over the tank. It will percipate calcium, It will inhibit calcification, and bind with most other elements in NSW. it also come it alot of forms (ie particulate, soluable, Inorganic organic, ortho and so on). P is truly one of the most important things in a reef tank to keep watch for. most folks dont.

I agree phosphate is definatley a concern for the reef tank keeper. I do beleive, however, that there are many ways of dealing with the issue, such as water changes, kalkwasser usage, skimming, use of macro algae, and use of phosphate removing filter media. As I stated above, my tank seems to be free of phosphate related problems. I'm sure there is phosphate in the tank, I doubt you'll ever see a tank free of it entirely. But it does not seem to cause problems in my tank, leading me to beleive that in fact my DSB does not absorb or hold phosphates in levels of consequence.


And here is where the two methodologies part company. You can biol it down to two choices at this point. One hand (dsb) takes waste/detritus and so on and puts it into a complex biochemical cycle for it to be exported by means of skimming, water changes, algal harvesting. and on the other hand one removes the waste/detritus and so on prior to decomposing and skips straight to export through the same basic methods. Also dont forget that with either system we all tend to have LR in our tanks, which is a solid source of denitrification unto itself.

take care and thanks for the good conversation

I agree that it is advisable to remove waste as efficiently as you can. I also believe that too much waste removal can actually be counterproductive in the reef tank. In a well maintained reef with a good deal of biodiversity (losts of scavengers, detrivours, ect.), and a reasonable feeding schedule, I think the issue of waste accumulation is minimal at best, and taken care of efficiently by such a tank.

Mojo....I'm curious, have you used DSB's in the past, and had negative experiences with them?

Thanks for posting with me :-D

Mike

[cich1]

thanks guys,between your debate and Chucks link to the article by Ronald Shimekle it will take me a week to digest this and a lifetime to understand, it is true that the more i read the more confused i become, also the more certain that i can do this

[MikeS]

thanks guys,between your debate and Chucks link to the article by Ronald Shimekle it will take me a week to digest this and a lifetime to understand, it is true that the more i read the more confused i become, also the more certain that i can do this

Well cich1, the subject of DSB usage is definately a complex and controversial one :-D Even the experts are still "learning" about DSB's. I posted this thread in the hope to get some good discussion on the subject ( I think we have that so far... :-D ), and for others to share their experiences with DSB's, both good and bad.

As for now, I still advocate DSB usage. This may change in the future, as we all learn more about them, or it may not. If you are interested in using a DSB cich1, keep doing what you are doing, research! A DSB is not a magic cure-all, and it must be properly set up and maintained. It also IMO works best in concert with macroalgae, kalkwasser use, skimmers, and good water change routines.

Cich1, feel free to ask questions, I'm sure we'll all do our very best to try to confuse you further :lol:

Mike

[mojoreef]

Yes Mike even knowing what I know I did play in the world of DSB's. I ran one for about 3 years. First couple of years were fairly trouble free in regards to it. in the third year I began to loose the battle with patches of cyano and algae, eventually the tank became more of a battle then a pleasure so I went back to what always served me best.

The issue of phosphates and DSB's is definately a controversial one. I have read many experts opinions, some say phosphates in DSB's is a problem, and others, like Dr. Ron Shimek, say that DSB's do not hold or accumulate phosphates. I suppose it all depends on who you beleive. I personally put a lot of faith in Dr. Ron's words, he seems to me to be the foremost advocate of DSB usage, and has done a great deal of research on the subject.
Ahh yes the good Dr., One of my favs, lol. Ron actually says that a dsb can not deal with P, all it does is to cycle it and facilatate the harvest of cyano and hair algae as the export system, not a very attractive choice to me. You do know that his dsb killed his tank after 3 years right?? Thier has actually been alot of scientific study done on DSB's fialing and being a source of generation of nutrients such as P and N. I can link you up if you wish.

Mike please take Ron with a grain of salt, his interest in the reefing hobby is not with the reefer in mind, if you know what I mean. In a recent debate with him on dsb's here are a few quotes from just one thread.
quote: on remote dsb's
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Having a 60 gal remote DSB may work, some folks can pull it off. I suspect, however, in most cases these turn into nutrient-sinks and will be problems in the long run.
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quote:this is his concept of how dsb's work, not very attractive
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It really matters because that is why a sand bed works. The material once captured by the animals in the bed really never leaves the bed. It cycles over and over in the bed from one organism in close proximity to another until the energy in it is used up and the material in it gets exported. The decoupling of these reactions allows the material to be liberated into the tank water where it will be food for, primarily cyanonbacteria, but other microalgae as well.
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quote:hmmm
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As an example of the flow necessary to move materials out of an "Acropora" thicket in nature, the flow across such a region has been measured, In the volume of a 100 gallon tank, that amount of flow would be on the order of 50,000 gallons per hour....
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quote:he says the dsb is finite
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The added feeding goes to maintain the DSB that would have been adequate if it were in the main tank. However, in this case, you have added more nutrients to the system and as the DSB is a finite system it becomes saturated and will not be able to export them adequately.
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when asked what kind of tank a dsb would support

quote:
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There is no magic number per gallon, but the actual number of fish per unit volume is pretty low. Probably on the order of no more than 3 or 4 relatively small fish per hundred gallon volume. Similarly coral diversity and abundance is pretty low.
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but he does let us know its simple

quote:
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If the hobbyist can't maintain a DSB in the main tank, which is about as easy as falling off a log, they shouldn't really try to maintain one in remote tank, but should probably try to use some other sort of filtration.
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but then 4 days later

quote:
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It is interesting that people tend to think that all of this is supposed to be "simple" and "easy" to do. Most folks don't realize that a coral reef ecosystem is the most complicated ecosystem on the planet, and that the sand bed component to it is also complicated. The level of complication is here is orders of magnitude more than is found in any manmade object, structure, or construction.
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oh here is one on the skimmers

quote:
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Yes, indeed. Then I did the research to show I was incorrect about skimming - A point I noted in presentations as well as in print.
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oooppps

quote:
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Personally, if I was culturing corals for reproduction I wouldn't use a sand bed.
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When asked how many detroviors to add to a DSB ron says

quote:
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The maximum amount of the most you can maintain..


take care buddy

Mike

[MikeS]

:D I've definately seen Dr. Ron's work picked apart before! :lol:

I'm aware both his work and he himself are considered controversial, and I always try to approach his stuff that way (belive me, I'm quite a skeptic at heart). I've tried to read as much about DSB's as I can from as many authors as I can. I guess what I like about most of Dr. Ron's writings is that they seem to make sense to me a bit more than alot of the anti-DSB stuff I've read out there. That, and what I have observed in my tank with the DSB (3 years, 4 months) seem to validate to me alot of his statements.

That's not to say that I don't buy any of the anti-DSB writing out there, some of it is quite convincing. I also don't think that keeping a DSB is completely risk free either. For the meantime, I think that the risks of a DSB, although present, are a bit overstated. I hope in a few years this issue will be definatively resolved one way or the other. Believe me, if my DSB fails and wipes out my tank, I'll be the first to admit I was wrong! :D

Mojo, when you began to have problems with your DSB, was it just cyano/algae problems or did you lose livestock as well?

Mike

[mojoreef]

Mike I dont think your tank will crash because of DSB failure. I have seen alot of those arguements before and most of them dont hold water (no pun intended) lol. As a dsb ages it will just loose its ability for nitrification and become fully anaerobic. What gets most folks is the algae problems.
I am not anti DSB, I feel that if folks know the limitations and cons of one they can work smarter in order to make thiers last longer. Even using a DSB as a sink is a viable option for a tank, sink the crud and deal with it later works. I aso like the look of sand in a reef tank, so for me if someone wants it purely for the way it looks it also fine by me. I just think knwing both sides of the story helps the individual deal with maintaining it better.

On my tank, it was two fold that moved me away from it. Algae was one for sure. the second was the leeching of Phosphates, I did not want to wait for that to start to effect calcification. so I just removed it and went back to bare bottom, which I had had up for over a decade.

take care mike and thanks for the conversation.

Mike

[MikeS]

Absolutely...thanks for joining us here! :D

I hope you will continue to post here at the forum!

Mike

[MikeS]

I felt I should add this fact about my DSB to the discussion as well....

My DSB is not a conventional DSB....it is made of approx. 4" of fine aragonite sand atop an existing approx. 2" of fine (<2-3mm) crushed coral. At the time I set up my DSB, this was the method recommended to me by several hobbyist I trusted, just to add the sand slowly over the course of several weeks on top of my existing CC substrate. According to the "experts" now, this method should not work well, if at all. However it has been in place for nearly 3.5 years and seems to function properly, my nitrates always test zero. Anybody's guess is as good as mine as to why it works :D :?:

I sometimes wonder if the larger grain size underneith the sand helps H2O diffusion through the sand bed a bit, helping cycle it faster through the DSB with a smaller amount of waste buildup. There has been virtually no migration of the larger CC grains towards the surface either, even in areas that have been disturbed by my clam feeding....he's large enough that when he contracts during feeding he can stir up the sand bed in spots pretty well.
Perhaps I'm getting only minimal or no denitrafication from my DSB at all, and the 0 nitrate tests (verified on seperate kits) are due to something else...I guess I really don't know for sure.

Well, I thought I should throw that out for thought... :D

Mike

[mojoreef]

Sounds about right Mike. I would imagine your getting good denotrification. I have never seen one stop doing that. What tends to happen over time is the loss of the upper aerobic zone as the anaerobic zone grows larger. Diffusion really doesnt happen to much in the lower depth if at all. That is why it is critical to make sure your have the abundance of critters in the bed, The main player for them are a type of worm that basically goes on deep dives into the substraight, it is his movements that allows for the migration of nitrates down and off gassing up.

take care

mike

[Paidbychrist0825]

Mojoreef, have you read the article on this forum about controlled plenum wasting?
I personally think that this would help reduce that"bad" anaerobic area at the bottom, by removing some of the anaerobic toxic water out, thus pulling out much of the bad phosphate that would be present at the bottom, along with pulling the water that may need filtered down into the sand to help this along. i have enclosed a link below

It seems to me that if you can remove the harmful things from underneath the sand, and keep it properly inhabited(IE lots of little critters in the bed) that you could(theoretically) keep one sand bed active and functioning for quite a long time.
o heres that link
http://www.coralforum.com/ftopic1521

[MikeS]

heres a pic of my DSB...you can see all the little worm tunnels, my DSB is littered with them. If you look, you can also see the CC under the aragonite.

[mojoreef]

LOL Paidbychrist0825 the author sure doesnt pull any punches. He has made a few errors in the write up, in regards to anoxic and anaerobic and so on but other then that he has the basic premise. He idea is strong but I believe what he has made is not going to do what he wants to it to do. But cudios for the idea.
Thier is a whole lot going on down thier and it is all bacterial driven. Most folks feel that the bacteria you have is better but in reality its not. Alot of other things come into play when bacteria is present in such magnatude. When using a fine particle substraight your not going to get the pulling like the author is looking for, the bonds and biofilms the bacteria live in are to tough, you will end up with little fissors of down puling water. I also dont think the suldide zone is really going to be come an issue as the author again says. It will never get to the very top of the bed, oxygen will kill them just prior. What you need to look at here is why are the sulfide reducing bacteria so high in the bed. That is the true story.
here is a post I did on Phosphates in a tank. take a peek it might give you a little clearer picture.

http://www.reeffrontiers.com/forums/showthread.php?s=&threadid=2672

[MikeS]

Mojo- in your opinion, do you feel it is impossible to achive a long term equilibrium between the aerobic and anerobic zones in a DSB?

Mike

[mojoreef]

Man Mike that is a tough question. it is possible but not as designed.

Mike

[MikeS]

Yeah, that's been one of my larger concerns about DSB's...as stated above, I don't worry too much about phosphates or toxicity with the DSB. IMO these are overstated and can be dealt with. The equilibrium between the zones, however, is something I have put some thought (and a bit of worry) into.

In a simple nutshell, here's my thoughts on that...

I think it is possible in a well maintained DSB to hit an equilibrium. Don't get me wrong, I don't just take this for granted as some of the very pro DSB folks do. I think the DSB is a very dynamic system, and must be treated as such. The worms are part of the key, to help diffusion and circulation. The more the better IMO. I think as long as the DSB has to adapt to smaller changes within itself (like water diffusion caused by worms...introduction of new nutrients into the DSB, periodic "mixing" of the anerobic and areboic zones, and gradual reintroduction of byproducts into the tank) it will equalize. It will definately fluctuate between the two ends, but I think if this process is ongoing, a long tem equalization can occur.

Another key I think is waste input into the DSB. I totally believe a DSB can be overwhelmed, leading to "failure"....but I think this is something the reefkeeper has a lot of control over. Not overstocking, conservative feeding, adequate scavengers and detrivores, skimming, macroalgae, and water changes can all help avoid an overloaded DSB. I'm working on the assumption that what goes into the DSB will eventually come out again, one way or another, given adequate diffusion and circulation in and out of the DSB. Limit what goes into it, and the end product will be limited as well.

These are my own thoughts on what can happen in a DSB under the correct conditions...

How's that for a rambling post? :lol:

Mike

[mojoreef]

Mike here is mine view of a dsb. I dsb is a ecosystem design to skew for the population of bacteria, both aerobic and anaerobic. It is not designed to export, with the exception of some nitrogen based products. Because of this all other stuff stays with in the bed beuried in biochemical cycles. through the leaching of P and othe organcs it will facilitate the growth of algae which can then be exported (nice in theory but ugly for a tank IMHO). What kills the dsb process is the tank itself, have a bottom and sides it does not allow for the migration of these organics, thus they go up. All the sand bed critters in the world are not goingn to do something about it, unless you export them, which most folks dont do.
See the concept of sand bed filtration is viable, the problem is that the constrants of the tank and system work against it. So for me if it could be designed from what it is to something that could give it a fighting chance it would be great. The author of the plenumn wasting article is on that path, but is using the wrong media.
Think about it Mike, if a fine sand bed is the extreme, and LR is the opposite, why not find a middle ground, say with a larger particle plenum style, with a waste removing feature built in, See to me this would bring the concept back into the for front of filtration, right now its a "to bad" type of thing.


Mike

[MikeS]

Thanks Mojo....good points!

Mike here is mine view of a dsb. I dsb is a ecosystem design to skew for the population of bacteria, both aerobic and anaerobic. It is not designed to export, with the exception of some nitrogen based products.

I fully agree. The ONLY reason IMO to consider a DSB in a reef tank is for nitrate reduction. I also agree there can be negative side effects, like you stated. Byproduct and waste accumulation, I think you and I would both agree, is probably the primary potentially negative effect of the DSB. How these wastes and byproducts are dealt with and their effects on the tank I think is where you and I start to see things a bit differently. I think these byproducts will eventually find their way back into the aquarium. I don't consider this an "export" of the byproduct, so much as a "recircultaion" of said byproducts. IMO some circulation of H2O thru the DSB, by worm tunnels and moderate sand sifting aids this process. Once re-released into aquarium, it must be dealt with by other means, like skimming, carbon, macroalgae, water changes, gas exchange, ect.

The real trick IMO is to get a long term balance between accumulation and re-release., ie the amount accumulating is not a great deal more than the amount being re-released back into the system. This is where I enter my "unsure" phase...but I think the best way to accomplish that is through a combination of reasonable H2O diffusion (enough to provide circulation though the DSB for byproduct removal, but not enough to greatly affect the areobic/anerobic zones) through the DSB and control of initial waste accumulation on/in the DSB in the first place. I wonder if this is why the 2 inches of fine CC under my aragonite seems to work...there is a greater amount of H2O based on DSB volume than an all aragonite DSB, aiding in said process.


Because of this all other stuff stays with in the bed beuried in biochemical cycles.

Do you think it really remains there, or do you think that it will eventually find its way back into the tank?

through the leaching of P and othe organcs it will facilitate the growth of algae which can then be exported (nice in theory but ugly for a tank IMHO). What kills the dsb process is the tank itself, have a bottom and sides it does not allow for the migration of these organics, thus they go up. All the sand bed critters in the world are not goingn to do something about it, .



I agree...in a way, I'm counting on that....there are ways to deal with and remove said wastes that the DSB can't deal with, and "helping" the DSB this way is necessary IMO....

unless you export them, which most folks dont do..

exactly! The byproducts and wastes that cannot be processed by the DSB must be exported by other means. I think a lot of reefkeepers don't understand this, I think that many of them choose a DSB believing it will be an all-in-one cure-all for their tanks, and then do not maintain the DSB properly or tanke the necessary steps to remove the wastes and byproducts.


See the concept of sand bed filtration is viable, the problem is that the constrants of the tank and system work against it. So for me if it could be designed from what it is to something that could give it a fighting chance it would be great. .

I also agree that the constraints of the tank can work against it. But I think if it is maintained, has the correct amount of diffusion through it, and isn't overloaded, it will work fine.


The author of the plenumn wasting article is on that path, but is using the wrong media.
Think about it Mike, if a fine sand bed is the extreme, and LR is the opposite, why not find a middle ground, say with a larger particle plenum style, with a waste removing feature built in, See to me this would bring the concept back into the for front of filtration, right now its a "to bad" type of thing.unless you export them, which most folks dont do..

I totally argree with you there....that is why I asked him why he was using a larger than normal (for a DSB) grain size...to aid diffusion through the bed. But I think there may be a "catch 22" with his idea...ie if the grain size is large enough to provide adequate diffusion for his plan to work, then his substrate bed will be too loose to see any significant de-nitrating benefits....as well as too loose to likely experience the byproduct accumulation issues that could be problematic for a DSB in the first place, making the idea of drawing off the plenum in a system like this unecessary IMO. Just a complicated UGF, I think.

Good points...... :-D

Mike

[mojoreef]

This is where I enter my "unsure" phase...but I think the best way to accomplish that is through a combination of reasonable H2O diffusion
Impossible to achieve my friend. The use of fine sand and the strength of the biofilm will not allow it. Even if you would want it to happen you dont want it back in the tank. See you have two very strong points here, which are the points that hurt a dsb. Soooo why not modify the system to be able to beat these two scenarios???????? Larger particles to help with diffusion?? drain/siphon system to remove collected unprocessed waste below the bed??? Its thoughts and modification like those that could bring this system back into the viable filtration light.
If you dont and you wish to run it as is then IMHO just run it as it was meant to be. "A sink" in which you sink all the problems until a point the bed can no longer deal with it any more, then just replace it.
Do you think it really remains there, or do you think that it will eventually find its way back into the tank?
Yes Mike I do, it will remain thier until it gets to a point where the bed is full and it losses its ability to perfom nitrification. Remember one other point. If thier is the presence of ammonia anywhere in the bed it will not allow for denitrification. Ammonia suppresses the first enzyme used by bacteria in the denitrification process. What ends up happening is that nitrates are converted to ammonium instead of gas. from thier it goes back to the N cycle and ammonium is processed down to nitrite and so on. This was the problem that Jeabert had with his plenum in Monaco and why he ended up opening them up to the ocean.
I agree...in a way, I'm counting on that....there are ways to deal with and remove said wastes that the DSB can't deal with, and "helping" the DSB this way is necessary IMO....
So I have to ask the question then. if your concepts of exporting are pretty much the same as mine (skimming/wc/siphoning and so on) why not do it prior to allowing it to rot in the bed?? lol you could skip alot of pain by removing it prior to rotting??
exactly! The byproducts and wastes that cannot be processed by the DSB must be exported by other means. I think a lot of reefkeepers don't understand this, I think that many of them choose a DSB believing it will be an all-in-one cure-all for their tanks, and then do not maintain the DSB properly or tanke the necessary steps to remove the wastes and byproducts.
So how do you remove these products mike?
I totally agree with you there....that is why I asked him why he was using a larger than normal (for a DSB) grain size...to aid diffusion through the bed. But I think there may be a "catch 22" with his idea...ie if the grain size is large enough to provide adequate diffusion for his plan to work, then his substrate bed will be too loose to see any significant de-nitrating benefits....as well as too loose to likely experience the byproduct accumulation issues that could be problematic for a DSB in the first place, making the idea of drawing off the plenum in a system like this unnecessary IMO. Just a complicated UGF, I think.
Ahhh we part company once again. This is where most dsb folks dont understand the dynamics of bacteria. Bacteria make thier own environments with thier biofilms and enzyme mass. You cannot view a sand bed as sand with water flowing through it. It is a huge blob of snot with sand mixed in. In a dsb the first 1" TO 1 1/2" of the bed is viable for nitrification and denitrification the balance is storage area only. Bacteria that perform denitrification will fix either oxygen and/or nitrates, they are faculative.
The most important thing you can do for a sand type substraight is to maintain its aerobic zone, the anaerobic zone will form no matter what through the build up of biofilms, enzyme mass, bacterial flock, particulate dus and so on. so with a large particle bed it would be easier to achieve. Why not instead of having such small article to maximize the population of bacterial surfaces just go with a little larger, you will achieve better diffision (which I can tell you understand the importance of) and still have a great nitrification/denitrification system. but you will also allow the unprocessed waste to sink down to an area where you can access it for removal???

good conversation


Mike

[MikeS]

Impossible to achieve my friend. The use of fine sand and the strength of the biofilm will not allow it. Even if you would want it to happen you dont want it back in the tank.

See, here we are looking at it from two different assumptions. My statements assume that the byproducts will eventually find their way back into the tank in one form or another, where yours do not. And yes, I do want it back in the tank, only hopefully in amounts that can be dealt with.


See you have two very strong points here, which are the points that hurt a dsb. Soooo why not modify the system to be able to beat these two scenarios???????? Larger particles to help with diffusion?? drain/siphon system to remove collected unprocessed waste below the bed??? Its thoughts and modification like those that could bring this system back into the viable filtration light.

You'll tend lose denitrating ability with the larger particles, won't you? also, if the diffusion through the bed is TOO rapid, won't the same thing happen?


If you dont and you wish to run it as is then IMHO just run it as it was meant to be. "A sink" in which you sink all the problems until a point the bed can no longer deal with it any more, then just replace it.

Thats assuming that a DSB is truly a "sink", with no way out...As we know, that's a debated subject... :-D
On replacement....do you think it could be viable to replace small amounts of the DSB at a time, spreading this process out over several weeks or months?


So I have to ask the question then. if your concepts of exporting are pretty much the same as mine (skimming/wc/siphoning and so on) why not do it prior to allowing it to rot in the bed?? lol you could skip alot of pain by removing it prior to rotting??


Yes...I can't argue that that is probably a very effective method of controlling pollution in the tank. The main concern I have with that is that if it is overdone, the biological filtration capacity of the tank will weaken and the system won't be able to handle increased pollution issues well. I think this method is TOO dependent on the reefkeeper. What happens if you can't get the crud out for a while for some reason, or some critter crawls into the rocks and dies where you can't see it? I like having the extra amount of bacterial filtration as a "cushion" against this, so to speak.


So how do you remove these products mike?

I'm still working on the assumption that these products do eventually find their way back into the tank water in one form or another....


Ahhh we part company once again. This is where most dsb folks dont understand the dynamics of bacteria. Bacteria make thier own environments with thier biofilms and enzyme mass. You cannot view a sand bed as sand with water flowing through it. It is a huge blob of snot with sand mixed in. In a dsb the first 1" TO 1 1/2" of the bed is viable for nitrification and denitrification the balance is storage area only. Bacteria that perform denitrification will fix either oxygen and/or nitrates, they are faculative.
The most important thing you can do for a sand type substraight is to maintain its aerobic zone, the anaerobic zone will form no matter what through the build up of biofilms, enzyme mass, bacterial flock, particulate dus and so on. so with a large particle bed it would be easier to achieve.
Why not instead of having such small article to maximize the population of bacterial surfaces just go with a little larger, you will achieve better diffision (which I can tell you understand the importance of) and still have a great nitrification/denitrification system. but you will also allow the unprocessed waste to sink down to an area where you can access it for removal???

Do you think my larger CC substrate under my sand might actually aid in this?

good conversation


Mike

I think so too! :-D

[mojoreef]

See, here we are looking at it from two different assumptions. My statements assume that the byproducts will eventually find their way back into the tank in one form or another, where yours do not. And yes, I do want it back in the tank, only hopefully in amounts that can be dealt with.
Well not much can be said then.

You'll tend lose denitrating ability with the larger particles, won't you? also, if the diffusion through the bed is TOO rapid, won't the same thing happen?
the common myth when it comes to this is that with the smaller grains you have more surface area for the growth of bacteria, true to a point but what they fail to tell you is that the bacteria does not live on the particles, they live in the biofilm and enzyme mass. This film eventually encompasses all areas between the particles, would matter to much the size of the sediment. So yes you will loose a little but for the slight loss and the great gain of fixing the problems associated with the finer particles its a big overall win. Mike the same arguement could be made to you, why dont you use mud??? the particles are even small then sand and thus more surface??? I think folks that use this type of system have to look at the negatives versus positives and draw a line some where.
Thats assuming that a DSB is truly a "sink", with no way out...As we know, that's a debated subject
Ah my friend thier is no debate, except by a few so called hobby experts with some money on the line. Thier have been countless scientific studies done by true Marine biologists that prove it is one. To be honest Mike the fact it is a sink can be a positive. I have a good friend (Marine Biologist) that runs one for the pure sake that it will sink.

On replacement....do you think it could be viable to replace small amounts of the DSB at a time, spreading this process out over several weeks or months?
No mike IMO you need to do it all at once for a couple of reasons. One you dont want to release the nasties that are trapped in the bed and expose your inhabitants to it. the other is that you want to not all replace the sand but the mass that inhabits it.

Yes...I can't argue that that is probably a very effective method of controlling pollution in the tank. The main concern I have with that is that if it is overdone, the biological filtration capacity of the tank will weaken and the system won't be able to handle increased pollution issues well. I think this method is TOO dependent on the reefkeeper. What happens if you can't get the crud out for a while for some reason, or some critter crawls into the rocks and dies where you can't see it? I like having the extra amount of bacterial filtration as a "cushion" against this, so to speak
you still have all the biological filtration that LR affords you. I would rather be more relient on myself then on bugs and bacteria that I have no control over, they can populate and die on thier own timeframe. just an example, if the power goes out on your tank, you have a mass of creatures respiring in that bed they will suck the oxygen out of that tank in a heartbeat??, or what if you have a die off in the bed?? you cant just get the syphon out and remove it like you could in a BB system. some thing to think about. On the critter dieing in the rocks, if its a snail or a worm or even a shrimp, who cares, they will be scavenged by other critter and the bacteria on and in the rocks, if its a bigger one like a fish, I would say any system user should leave that in thier.
Do you think my larger CC substrate under my sand might actually aid in this?
Not sure Mike, bottom line is that if its all still sitting thier it will fill no matter what sized particles you have done thier. the concept would be to design something that could remove the crude.


mike

[MikeS]

Great converstion! :-D

Well not much can be said then.

Yeah...no point in us debating that one back and forth forever! You'll understand why I believe what I do further in this post . :-D

the common myth when it comes to this is that with the smaller grains you have more surface area for the growth of bacteria, true to a point but what they fail to tell you is that the bacteria does not live on the particles, they live in the biofilm and enzyme mass. This film eventually encompasses all areas between the particles, would matter to much the size of the sediment. So yes you will loose a little but for the slight loss and the great gain of fixing the problems associated with the finer particles its a big overall win.

I understand the biogoo/enzyme thing ( I majored in Biology, I wanted to go to med school, but it didn't work out :( ) Surface area issues aside, one reason I believe smaller particles are a more efficient media in a nitrate reducing system has to do with maintaining a reletively undisturbed anareobic zone. Larger partices=more H2O diffusion throughout the substrate=disruption of the anareboic zone. I think a small amout of disruption is a good thing, but too much will simply shut it down.

Mike the same arguement could be made to you, why dont you use mud??? the particles are even small then sand and thus more surface??? I think folks that use this type of system have to look at the negatives versus positives and draw a line some where.

Agreed. By that logic, mud would be a better substrate, IMO I think it has to do with the impracticality of using such a fine substrate...I mean your tank would always be a cloudy mess....who wants that? :-D


Ah my friend thier is no debate, except by a few so called hobby experts with some money on the line. Thier have been countless scientific studies done by true Marine biologists that prove it is one. To be honest Mike the fact it is a sink can be a positive. I have a good friend (Marine Biologist) that runs one for the pure sake that it will sink.

Could you give me a few links to some good studies on the subject? After all, for me this is all about learning new things, and I'd like to read them! :-D I'm stubborn, but not to the point that I'm unwilling to learn, nor to the point where I would sacrifice my tank to prove a point. :-D
Ok...here I'm puzzled. I mean I see how this could definately be the case, based on certain assumptions. Yet something I have observed in my own tank on two seperate occasions tends to condradict that statement....please let me know what you think of this...

I have totally drained and moved my reef tank twice with the DSB intact. One of the moves was across town....with the tank (empty of water, but DSB intact) riding in the back of a truck. When removing the LR both times, the sand bed was significantly disturbed. Some of the base rock had settled 2/3 to 3/4 of the way to the bottom of the bed. The bed was further disturbed in the actual moving process. On the last move, I had to go down a steep flight of stairs...a good deal of the sand "flowed" to the other end of the tank. When I got the tank placed, I smoothed out the DSB (suprisingly the CC remained at the bottom, with not much integration) and added the water, further distrubing it. In a nutshell, the DSB was greatly disturbed in a very short period of time. The water was cloudy, I could smell the hydrogen sulfide, ect.
A large amount of whatever nutrients/wastes/byproducts/toxins exisited in the DSB undoubtedly were released into the tank.

However, on both occasions, I experienced no significant cycle and no livestock loss in the newly moved tank, only a small rise in nitrates and a few patchy cyano outbreaks. Both were minor and short lived...within 2 weeks the tank was back to normal....0 nitrates and no cyano.

That's what puzzles me...if the DSB is such a nutrient sink and traps all these nasty byproducts, why didn't I see far more pronounced and serious results after moving the tank? (btw the last move the DSB was 2 years old). I'd like your opnion on this...I do base alot of my statements on what I have observed on my own DSB...

No mike IMO you need to do it all at once for a couple of reasons. One you dont want to release the nasties that are trapped in the bed and expose your inhabitants to it. the other is that you want to not all replace the sand but the mass that inhabits it.

Ok...now my idea of replacing the DSB bit by bit is based alot on my observations of what happened (or didn't happen) during the move of the tank. When I say "small" amounts...I mean pretty small amounts...like a few cups at a time...done in a grid pattern, maybe biweekly with water changes....

you still have all the biological filtration that LR affords you. I would rather be more relient on myself then on bugs and bacteria that I have no control over, they can populate and die on thier own timeframe. just an example, if the power goes out on your tank, you have a mass of creatures respiring in that bed they will suck the oxygen out of that tank in a heartbeat??, or what if you have a die off in the bed?? you cant just get the syphon out and remove it like you could in a BB system. some thing to think about. On the critter dieing in the rocks, if its a snail or a worm or even a shrimp, who cares, they will be scavenged by other critter and the bacteria on and in the rocks, if its a bigger one like a fish, I would say any system user should leave that in thier.

I take your points. Myself, because of the demands of my job, kid, ect, I am admittedly negligent from time to time on maintenance...nothing extreme, mind you, but there are times where water changes don't happen as often as they should, ect. A system that dependent on ME would suffer from time to time, definately not ideal, but I'm honest. :-D

I'm enjoying our conversation...it's so nice to debate a controversial subject with somebody who does so in a civil manner and trys to remain reasonably objective ... :-D


Mike

[mojoreef]

I understand the biogoo/enzyme thing ( I majored in Biology, I wanted to go to med school, but it didn't work out ) Surface area issues aside, one reason I believe smaller particles are a more efficient media in a nitrate reducing system has to do with maintaining a reletively undisturbed anareobic zone. Larger partices=more H2O diffusion throughout the substrate=disruption of the anareboic zone. I think a small amout of disruption is a good thing, but too much will simply shut it down.
Ahh Mike your still not getting it. the biofilm/goo / mass is the anaerobic zone. its heavier then water and will not be effected by diffusion. think lava lamp, hehehe. You could have an old chunk of food sitting on the sand, as the bacteria form on it so does the biofilm, once the film is complete the whole darn thing is anaerobic. DSB's are not static they are always in a state of flux whe it comes to bacterial popluations and the byproducts that come in with them.
Agreed. By that logic, mud would be a better substrate, IMO I think it has to do with the impracticality of using such a fine substrate...I mean your tank would always be a cloudy mess....who wants that?
LOL see and that is exactly what I think of a dsb, :lol: I keep my partlicle size in the 5 to 50lbs size and call them rocks.
That's what puzzles me...if the DSB is such a nutrient sink and traps all these nasty byproducts, why didn't I see far more pronounced and serious results after moving the tank? (btw the last move the DSB was 2 years old). I'd like your opnion on this...I do base alot of my statements on what I have observed on my own DSB...
Good question. As you have history in biology you know their are several reasons. First and foremost is the biofilm entrapment. When you distrubed it you definately did release an ammount of nasties, but your going to have to look at them individually in order to see what may have happened to them. on the sulfur, I would imagine that you off gassed and ammount and then bound up the balance with the elements of the salt water, magnesium primarily. On the P probilby the same thing except bound them to calcium, then bound some up in algae, sank some back into the biofilm, and left some free. the reason you had a minor cycle is probibly becasue you killed the bacteria in the aerobic zone through oxygen depervation. thus a small nitrification cycle. Lots of reasons and could be's mike.
Ok...now my idea of replacing the DSB bit by bit is based alot on my observations of what happened (or didn't happen) during the move of the tank. When I say "small" amounts...I mean pretty small amounts...like a few cups at a time...done in a grid pattern, maybe biweekly with water changes....
See mike I would never endanger one of my prize corals or fish for all the bugs and bacteria in my sand. so its kind of a pesonal choice thing for each individual.
I take your points. Myself, because of the demands of my job, kid, ect, I am admittedly negligent from time to time on maintenance...nothing extreme, mind you, but there are times where water changes don't happen as often as they should, ect. A system that dependent on ME would suffer from time to time, definately not ideal, but I'm honest
Mike my water is originally from the ocean and I have not changed it in three years, so dont feel bad about the WC's :wink:

Mike

[MikeS]

Ahh Mike your still not getting it. the biofilm/goo / mass is the anaerobic zone. its heavier then water and will not be effected by diffusion. think lava lamp, hehehe. You could have an old chunk of food sitting on the sand, as the bacteria form on it so does the biofilm, once the film is complete the whole darn thing is anaerobic. DSB's are not static they are always in a state of flux whe it comes to bacterial popluations and the byproducts that come in with them.

No, I get what you are saying...
but this biogoo, logically, cannot be totally H2O impermiable. There has to be H2O diffusion (along with the nutrients saturated in it) through this goo, at what rate and to what degree may be of question, but the diffusion must exsist. If it didn't, the bacteria within it would either quickly starve and die, or suffocate on its own wastes.

See mike I would never endanger one of my prize corals or fish for all the bugs and bacteria in my sand. so its kind of a pesonal choice thing for each individual.

Me either...that's why I have not tried it yet... :-D


Mike my water is originally from the ocean and I have not changed it in three years, so dont feel bad about the WC's :wink:

Well, that's a subject for another thread... :lol:

Your nutrient export methods should lend themselves well to a no water change tank...but how do you deal with replenishing used up trace elements?

Mike

[mojoreef]

No its not impermiable, but with the binds it has to the substriaghts its not going to flow away either. So pathways are to be expected through out. As per waste and nutrient transmissions, now you can start to see the importance of the critters that live with in the bed itself, Ie worms, pods, and so on.
Bottom line Mike the DSB system as designed is very flawed. However the concept could be very viable,but it needs to be tweeked and redesigned to make it deal with the problems it has and thus extend its lifespan. Personally I dont know why folks are so stuck on leaving it exactly the way it is, why not make a few sacrifices and come up with a sediment system that is actually designed to work in a closed reef tank, instead of trying to mimic that of a lagoonal bay?? If you want a true reef type system and wish to mimic that, then sand is not in the equation.


Mike

[MikeS]

No its not impermiable, but with the binds it has to the substriaghts its not going to flow away either. So pathways are to be expected through out. As per waste and nutrient transmissions, now you can start to see the importance of the critters that live with in the bed itself, Ie worms, pods, and so on.

Yes...the critters are extremely improtant to the function of a DSB. I also recoginze this as a potential weakness, the bed is highly dependent upon them.

Bottom line Mike the DSB system as designed is very flawed. However the concept could be very viable,but it needs to be tweeked and redesigned to make it deal with the problems it has and thus extend its lifespan. Personally I dont know why folks are so stuck on leaving it exactly the way it is, why not make a few sacrifices and come up with a sediment system that is actually designed to work in a closed reef tank, instead of trying to mimic that of a lagoonal bay?? If you want a true reef type system and wish to mimic that, then sand is not in the equation.

I'd say "imperfect" myself. :-D But I have never maintained that the DSB was an all-in-one solve all your problems method. It defiantely has shortcomings and imperfections, but it has done exactly what it was supposed to do in my tank for over 3 years now, with no negative side effects. Hopefully it will continue to do so.

I agree, the DSB could be improved. I'm not sold on the plenum wasting idea, I still think in order for it to function properly mechanically in the long term, the grain size in the substrate would have to be too large to provide adequate denitrafication. Maybe a stratified substrate like mine, but with the pull I think migration would be too big a problem and it would not work for long.

The idea that a DSB mimics anything that exsits on a natural reef is where I part company with most other pro-DSB reefkeepers. I think that the ecological dynamics of the real reef are consideralbly different and more complex than anything we could possibly hope to achive in a reef tank. I don't think the DSB is "natural", ...other than the fact that it is also made of sand like the reef bottom :-D . nor do I feel it very closely duplicates the biological processes that actually take place on the reef. The constraints of the tank are just too great of a factor for that to be the case IMO. To me, comparing what we have in our reef tanks to a real reef is kind of like sticking a frog in a jar with some mud and sticks, and calling that a microcosm representative of the swamp the frog came from. Yes, we all try to strive for creating as natural of an environment as we can in our reef tanks, but I think we fall short.

BTW, I saw the pictures of your tank on your website....very impressive indeed! :-D You have a very beautiful tank!

Mike

[Charles Poole]

Aside from Nitrate, what food source do De-nitrifying bacteria require in order to breakdown Nitrate into Nitrogen and Oxygen?

Also, without all the diffent micro-fauna in a DSB, then it is not going to be a "functional" DSB. A "functional" DSB has sufficient depth, grain sizes, and water dispersion capabilities, to effectively process foods and wastes into bio-available wastes, for further biological breakdown and transferrence.

This means that if the key components to a DSB are likely things that will not fall into the average reef tank. Nitrifying bacteria are present in the atmosphere. No matter how pure you make your tanks water ( fresh or salt ), eventually it will become biologically active with wastes and nitrifying bacteria.

The micro-fauna that consume the waste products of some bacteria, and further break it down to be usable by other bacteria, which in turn start this process over again with another set of micro-fauna and bacteria. etc. etc. etc.

Water flow in enclosed areas has not been given a whole lot of attention in this hobby. There are many referrences to how much current is acceptable, even that chaotic currents are best. But little is ever explained about how to get the water to specific flow patterns. A DSB needs a flow strong enough to push water fairly deep into it, without disturbing the sand.

Aiming powheads and returns at 45 - 55' angles towards the surface of the tank, will do an incredible job at creating a strong downward motion of the water that is nearest the surface to air gas exchange area. This in turn carries well oxygenated water down towards the sand bed. This perpendicular current, is forced further into the DSB than a similar strength parallel current would.

As far as Phosphate goes, the less you add, the less your system has to learn to cope with. If you a sure that you are not over feeding your tank, then it is likely over stocked, or current is not strong enough. ( Orthophosphate ) Inorganic Phosphate is the algea producer. It is highly bio-available, and necessary for most every living cell. It goes into a cycle in the aquarium, going back and forth between Inorganic and Organic forms, unless it is exported. Protein skimmers do an excellent job of removing Inorganic Phosphates, which helps to lower the risk of algae plauge, and reduces the amount that can be converted back into the organic form. Without a skimmer, I feel it is wise to grow and harvest macro algaes for the primary means of phosphate removal. Secondary would be proper water motion, to keep unwanted elements from collecting in the DSB in the first place... :)

Chuck

[MikeS]

To be honest, I'm not 100% sure on the bacteria question Chuck, but I think these bacteria are fairly nutrient-specific.

Sounds like you are basicaly on the same page as I am Chuck...limit what goes in and the output will be limited as well...

Mike

[Charles Poole]

Yep. :)

If you have to add enough bad things to the tank to keep the fish well fed, that excess nutrients are not cycled fast enough, then you need to decrease your overall bio-load.

Some times less is really more...

[mojoreef]

I still think in order for it to function properly mechanically in the long term, the grain size in the substrate would have to be too large to provide adequate denitrafication. Maybe a stratified substrate like mine, but with the pull I think migration would be too big a problem and it would not work for long.
You should shoot Charles Delbeek a email he set one up on the 1500 gallon reef tank in the hawaian aquarium, its been up for years, maybe he could shed a better light then I.

other than the fact that it is also made of sand like the reef bottom
No sand on a reef Mike, maybe you are thinking about a lagoon or a bomii???

Thanks for the kind words on my tank, I appreciate.

The micro-fauna that consume the waste products of some bacteria, and further break it down to be usable by other bacteria, which in turn start this process over again with another set of micro-fauna and bacteria. etc. etc. etc.
Hi charles. Bacteria dont really need microfuana in order to do thier job, they actually could view them as competitors. what the microfuana do do is to help migrat food to the bacteria through thier movement.

Charles strong post on P. I agree with most of what you say. the P cycle is usually all animal to algae and back again. Example: IP become available (lets say from the disalution of IP from the sand itself) this is bound up right away by bacteria. thier popluations will bloom in order to meet the food demand. as the IP becomes bound up by them it becomes less and less, the result is a rapid death of the bacterial population due to starvation. With this death all the IP that was once bound by the bacteria then is released. usually the first on the job is cyano, the reefer will begin to see spots of cyano here and thier, nothing to really worry about. maybe a touch of hair algae to. the algae will do the same as the bacteria, they will bloom to meet the current available IP (food). once used up the algae will begin to recede and die off, as it dies the bacteria once again jump on to the new food source and begin to reduce the rotting algae. this cycle continues and continues, but as we continue to feed our tanks the IP input continues to enlargen the cycles and make them more dramatic.
On the skimmer I again agree its a great means of export, but how my friend does it get to the IP that is cycles in and on the surface of the DSB???? Unless you release the IP from the dsb how can it pass through the skimmer?? The bacteria and algae in and on the surface of the bed are not going to give it up or allow it to pass, its thier only source of food its limiting to them.
Aside from Nitrate, what food source do De-nitrifying bacteria require in order to breakdown Nitrate into Nitrogen and Oxygen
It doesnt work that way Charles. Only Nitrates can be converted into notrogen type gasses and nothing thier gets turned into oxygen. Example:
Food enters the bed and it set upon by nitrifing bacteria, they begin to reduce only the portions of the products that are nitrogen based, all other things are sunk into the bed through diffusion, gravity and fuana movement. Ammonia is reduced to nitrite by oxidizing ammonia ions, then another type of bacteria reduces it further to nitrates by the same means. these two bacteria can only live in oxygenated water (aerobic). From here the byproduct nitrates are released. The bacteria that can educe them perfers oxygen and will use it first. as the oxygen is removed form their enviroment they have the ability to convert to the reduction of Nitrate instead (they are called faculative: able to live with or with out oxygen). If no ammonia is present in thier enviroment they have the ability to release a enzyme that will allow them to convert nitrates to nitric oxide gas, which is reduced to nitrous oxide gas, which is reduced to dinitrogen gas. Any of these gasious form of nitrogen can be released into the bed and then up and out. If any trace amount of amounia is found in thier enviroment it will not allow for the release of the first enzyme needed for the process of denitrification (which is what I believe happens in most hobbists dsb's) what happens then is that instead of converting the nitrate to gasious compounds the nitrate is converted to ammounium. The ammounium is then returned to the top of the nitrogen cycle and is once again converted by aerobic bacteria to nitrite, and will continue to cycle and grow in the scale of cycle.


hope it helps


mike

[Charles Poole]

Hello Mike, good to meet you. :)


It doesnt work that way Charles. Only Nitrates can be converted into notrogen type gasses and nothing thier gets turned into oxygen.


OK, I see your point partially. You are correct that the oxygen is used up by the de-nitrifying bacteria during the breakdown process. But, The bacteria needs to have a supply of food in order to create this breakdown process. Simple sugars, even alcohol will do the trick, or some other carbohydrate food sources found in the DSB.

*** The result of de-nitrifying that happens to rapidly, is Hydrogen Sulfide. Which means that a DSB that is a converts Ammonia full swing back to Nitrogen gas, runs the risk of creating excess Hydrogen Sulfide. This is simply due to nature, and con be avoided by reducing the overall amount of Nitrate that the DSB has to convert in the first place. ***


Bacteria dont really need microfuana in order to do thier job, they actually could view them as competitors. what the microfuana do do is to help migrat food to the bacteria through thier movement.


Could be competitors, but they are beneficial in the "BIG" picture of a functional DSB. Through there actions, oxygenated water is able to reach further into the sand bed. They also eat bacteria, algae, detritus, which also benefits the sand bed, and the system as a whole. This is the basis for Dr. Shimeks ideal DSB.

No sand on a reef Mike, maybe you are thinking about a lagoon or a bomii???

How deep have you dived? The areas surrounding the bottom of most reefs is very sand/silty. This sand is the result of biological breakdown, parrot fish and other animals that chew the reef, and leave "sand" particles in there wastes. A reef is an ecosystem, and as such, all aspects need to be considered. From the very top to the very bottom... :)

This has really turned into a very informative thread... :)

[MikeS]

You should shoot Charles Delbeek a email he set one up on the 1500 gallon reef tank in the hawaian aquarium, its been up for years, maybe he could shed a better light then I.

Yes, I'm interested in learning some of the specifics of a working model of this system...how would one go about getting ahold of him?


No sand on a reef Mike, maybe you are thinking about a lagoon or a bomii???

:?: :?: I've logged quite a few hours scuba diving all around the Caribbean, just about every reef floor I have seen is sand.

Thanks for the kind words on my tank, I appreciate.

Credit where credit is due! :-D

All of this is reminding me exactly how much I have forgotten since college...that was 10 years and a lot of beer ago.... :D

I hate when people make me think too hard.... :lol:

Mike

[mojoreef]

Good to meet you to charles
OK, I see your point partially. You are correct that the oxygen is used up by the de-nitrifying bacteria during the breakdown process. But, The bacteria needs to have a supply of food in order to create this breakdown process. Simple sugars, even alcohol will do the trick, or some other carbohydrate food sources found in the DSB.
Nope.The anaerobic bacteria perfer to fix oxygen. In saying they fix it I mean they convert oxygen to energy (thats thier food sort to say). When the oxygen runs out they have the ability to fix nitrate insteed, again that is their food or energy source. This whole process is basically the transfering and stealing of electrons. they dont eat like I think you think?? In the case of nitrification, bacteria steal electrons through oxidization. Nitrosomonas bacteria oxidizes ammonia converting it from NH4 to NO2
*** The result of de-nitrifying that happens to rapidly, is Hydrogen Sulfide. Which means that a DSB that is a converts Ammonia full swing back to Nitrogen gas, runs the risk of creating excess Hydrogen Sulfide.
Charles this is something I have never heard before, do you have anything I can read up on??
Could be competitors, but they are beneficial in the "BIG" picture of a functional DSB. Through there actions, oxygenated water is able to reach further into the sand bed. They also eat bacteria, algae, detritus, which also benefits the sand bed, and the system as a whole. This is the basis for Dr. Shimeks ideal DSB.
Yes that is what I had said. but that is really thier only true purpose, they excrete almost all of what they intake. A problem with these critters is something called recruitement. because of the size of the bed and the fact that it is a closed system, you will in short time run out of these critter and have to continue to replenish the stock of these critters.
How deep have you dived? The areas surrounding the bottom of most reefs is very sand/silty. This sand is the result of biological breakdown, parrot fish and other animals that chew the reef, and leave "sand" particles in there wastes. A reef is an ecosystem, and as such, all aspects need to be considered. From the very top to the very bottom...
Actually Charles I have dove of dozens of reefs, in a lot of different countries. I can tell you from my experence if you see sand you very rarely see corals. In lagoonal envirments you will find some soft corals and a few types of LPS. In bomii reefs you will find corals on the small rock formations but nothing on the sand. In most cases in the worlds reefs sand usually means the death of a reef.


mike

[MikeS]

Nope.The anaerobic bacteria perfer to fix oxygen. In saying they fix it I mean they convert oxygen to energy (thats thier food sort to say). When the oxygen runs out they have the ability to fix nitrate insteed, again that is their food or energy source. This whole process is basically the transfering and stealing of electrons. they dont eat like I think you think?? In the case of nitrification, bacteria steal electrons through oxidization. Nitrosomonas bacteria oxidizes ammonia converting it from NH4 to NO2

Now I'm confused. I thought most truly anerobic bacteria simply go dormant in the presence of an oxygen rich environment, and that their ability to fix nitrogen is the primary compensatory method by which they survive in a low oxygen/ oxygen free environment.


Yes that is what I had said. but that is really thier only true purpose, they excrete almost all of what they intake. A problem with these critters is something called recruitement. because of the size of the bed and the fact that it is a closed system, you will in short time run out of these critter and have to continue to replenish the stock of these critters.

Assuming they are not overly predated against, are adequately fed, and can reproduce, why would you run out of said critters? I do see swings up and down in populations of the visible sand bed critters (I'm currently in an upswing), but I've never seen a lasting decline.


Actually Charles I have dove of dozens of reefs, in a lot of different countries. I can tell you from my experence if you see sand you very rarely see corals. In lagoonal envirments you will find some soft corals and a few types of LPS. In bomii reefs you will find corals on the small rock formations but nothing on the sand. In most cases in the worlds reefs sand usually means the death of a reef.

Hmmm....are we perhaps talking about two different things? I've dove just about every imaginable place in the Caribbean....every reef there I have seen rises out of a sand bottom. I don't recall seeing any lone corals growing on the sand itself...but the reef "structures" have a sand bottom at the base....

Mike

[mojoreef]

Now I'm confused. I thought most truly anerobic bacteria simply go dormant in the presence of an oxygen rich environment, and that their ability to fix nitrogen is the primary compensatory method by which they survive in a low oxygen/ oxygen free environment.
I here ya Mike. to be honest thier are bacteria that can denitrify under fully aerobic conditions. Its all about the nitrite reductase. I will find you a link to discribe it a bit.
Assuming they are not overly predated against, are adequately fed, and can reproduce, why would you run out of said critters? I do see swings up and down in populations of the visible sand bed critters (I'm currently in an upswing), but I've never seen a lasting decline.
Its called recruitment..a simpler term would be survival of the fittest. In the case of DSB's in folks tanks, it all boils down to a single type of worm. If you have the ability to read through an author called SOROKIN that would be best. he has done very in depth and long term studies on the subject. YOu could also ask Ron for possibly a simpler answer.
Hmmm....are we perhaps talking about two different things? I've dove just about every imaginable place in the Caribbean....every reef there I have seen rises out of a sand bottom. I don't recall seeing any lone corals growing on the sand itself...but the reef "structures" have a sand bottom at the base....
Mike what kind of a reef in the caribbean??? hehehe

Mike

[MikeS]

I here ya Mike. to be honest thier are bacteria that can denitrify under fully aerobic conditions. Its all about the nitrite reductase. I will find you a link to discribe it a bit.

That's what I thought. Don't the bulk of the anaerobic bacteria in the DSB fall into this category?

Its called recruitment..a simpler term would be survival of the fittest. In the case of DSB's in folks tanks, it all boils down to a single type of worm. If you have the ability to read through an author called SOROKIN that would be best. he has done very in depth and long term studies on the subject. YOu could also ask Ron for possibly a simpler answer.

Where can I find the Sorokin writings? I'd like to read them. A bit technical are they? I'm fully aware that biodiversity in the DSB drops off over time, as a result of certain critters out-competeing others for available resources....

Mike what kind of a reef in the caribbean??? hehehe

Ahhhh mojo...I feel you reeling me in... :lol: what is wrong with my statements?

Mike

[Charles Poole]

The result of de-nitrifying that happens to rapidly, is Hydrogen Sulfide


This was taken out of Martin A. Moe Jr.'s book "The Marine Aquarium Reference". There is a section on denitrification that explains the process of the individual aspects of Nitrification and denitrification.

I have no formal schoooling, so I admit I have to rely on "common sense" and trusted authors. And of course, trial and error....

[MikeS]

bump...

[Condiman]

After reading all of this I am going to need a week to recover. :w00t:

[gman0526]

Thought I share some pics of my DSB in the refuge and some pics of the critters than inhabit the DSB in my main tank.

Fuge DSB
http://img.photobucket.com/albums/v605/Gman0526/fugelayrs.jpg

http://img.photobucket.com/albums/v605/Gman0526/dsbfuge3.jpg

http://img.photobucket.com/albums/v605/Gman0526/dsbfuge2.jpg

Worms at work

http://img.photobucket.com/albums/v605/Gman0526/dsb5.jpg

http://img.photobucket.com/albums/v605/Gman0526/dsb3.jpg

Picture of the tank after adding about 1" of new sand. (2wks ago)

http://img.photobucket.com/albums/v605/Gman0526/30gft1.jpg

[mojoreef]

Nice tank GMAN!!

MIke

[gman0526]

TY Mike. That compliment means a lot coming from you :-D Only wish one day to be able to set up something in the scale of your monster.

[mojoreef]

Ahhh it doesnt have to be a monster to be a heathly beautiful reef


Mike

[MoonSoft]

I go a route that most would cringe at... i use about a 2-4" DSB ,made of pure oolite.. very fine stuff..... i have noticed something interesting about it.. :) massive bubbles coming up from the bed when i feed the day prior.. from what i have read about nitrogen cycle, this could be two things.....
Hydrogen sulfide... from anoxic enviroments, or it could actually be the nitrates breaking dowin into nitrogen and oxygen offgassing...

i have had the bed for about 5 months with no real poblems even when i stir the entire bed every once and a while to move out sediment into the water column... some corals benefit from this but i do perform a flushing of the SPS after these events, and it ussually a filter change/wash follows the event.

[MoonSoft]

let me also say i do not nor have i ever employed the use of a plenum. Nothing against them i just didn't see the point.

[funkybozu]

my DSB took 3 months to gtart to work. and i think it was the addition of the MH that made the diff.

[gman0526]

funkybozu, when you say it took 3 mos. to work what do you mean? That's when you got to see some bubbles forming withing the DSB or that's when you noticed a decrease/change in water chemistry?

[funkybozu]

bubbles and change in chemistry
i also had this black line in the bottom half of the BSD, that went away as soon as i had the MH on 10/24.
the cycle didnt take long (a month i think) then before i put a skimmer on
i had pikes in trates. then with the skimmer, a got a steady increase
in trates, so i water changed.
as soon as the MH was on, no trates no black sand, and bubbles forming like crazy.
i also noticed a decrese in Calc that i didnt have before.
and i dont have huge algea breaks any more.
i do have some hair algea but thats soon eaten by my clean up crew
btw. that an other thing, i think it took 3 months to stabilise because
it prob took that long for the LR to seed the sand.
i read that every year you need to get a detrivor pack to refill the life stock, or change half your sand.... not looking forward to it

[MikeS]

Moon....my DSB is somewhat similar...4 inches of oolitic aragonite on top of 2 inches of CC...

The bubbles are most likely nitrogen gas escaping...if it was hydrogen sulfide you'd probably be able to smell it....hydrogen sufide is detectable to the human nose in parts per billion...you get that very distinctive "rotten egg" smell....

Funky....I'd imagine that the timing of adding the MH's and the reduction of nitrates in your tank was most likely just a coincidence. DSB's take awhile to get going...the bacteria in there work rather slowly, and it takes awhile for them to build up a population....

Mike

[MoonSoft]

Well then i can assume it's the Nitrates breaking down as most people have told me happens when you run a DSB, but i ALSO noticed that the bubbles stopped comung up like crazy after the addittion of MH lighting.. i can assume the light penetrating the DSB would probably have changed the types of algae that are populating it, or it could be just the cycling process that takes place in new tanks.. i added my MH setup at about 4 months of DSB, so i am not sure...

I am getting ready to install one of those Wave 2K devices, have you seen this thing!!! WOW!!!!! replaces ALL powerheads

[mojoreef]

Moon its mostly likely CO2 and maybe some nitrogen gas. The addition of the MH's probibly started up some algae colonies which are now using up the co2 instead of letting it off gas.

hydrogen sulfide gas take alot to form and even more to gas up. So I dought it was that. Black sand can be from hydrogen sulfide but also different forms of algae to. Easy way to test is to take a pinch and smell it. that will tell ya.

MIke

[funkybozu]

it smelled of rotty eggs, lol you would not beleave how bad that was in the car ,when i had to move the tank

[mojoreef]

then it was hydrogen sulfide, nasty stuff.


mike

[MikeS]

Moon its mostly likely CO2 and maybe some nitrogen gas. The addition of the MH's probibly started up some algae colonies which are now using up the co2 instead of letting it off gas.

Good catch mojo....I missed that one....

Mike

[gman0526]

If there's any thread in this forum that needs to be brought back ;) if not for discussion at least for reference.

FWIW I've been BB for the last 1 yr 2 mos. and loving it.

[Gottcha]

im bb myself....also having no problems and loving it

[MikeS]

agreed George...I saw the last days of my DSB and now have a BB tank, have observed alot since that last post... :)

MikeS

[specsgirl]

I too agree that I'm lovin my BB tank! There's no comparision in my mind.

[icereefer]

I liked my DSB, that I never had any problems with because I always kept a good working crew living in my DSB's but I do have to agree, BB is so much easier. less maintance.