New Nitrate theory

[Paul B]

I had a sand bed in a tank for right at 10 years before I finally tore it down last fall to upgrade to a larger tank. Though I'm not sure it qualified as a "DSB" since it seems to be a rather broad term. It contained anywhere from 1" to 3"

Tulsa, conisidentially, the author said to me that 1' to 3" for a DSB is perfect. That is not really the depth of a DSB he is talking about.
I think more like 4" and deeper, acording to the author "may" be a problem.
He also did not say that this will always happen in a deeper bed, although I don't know why.

As for live rock, I happen to disagree with him on that point and feel you can't have too much live rock. I don't think rock and deep sand would qualify as the same thing. But much of my rock is hollow because I built it like that. Not for nitrate reduction which I diden't think about at the time, but just because it is easier tio build like that.

Capn, Bob seems to think from his research or more likely, the research of the people he quotes that this problem with the anerobic bacteria in deeper areas where there is almost no oxygen at all harbors bacteria slightly different from the anerobic bacteria we have always known about that just turn nitrate into nitrogen gas which disapates out of the water. This other bacteria convert the nitrogen gas back again into ammonium which the shallower bacteria again convert back into nitrates.

I am only posting the article I did not write it but I feel that too many DSBs have nitrogen problems where there should be none.
This sounds like a plausable theory to me other wise, where is the nitrate coming from in a tank with a DSB?
Again, if a DSB is not working and we have a nitrogen problem, what exactly is the DSB doing?
There should be way more nitrates in my tank than a tank with a DSB and that is not always the case. Maybe this theory
(which I did not write) is true.
:smokin:

 

[TulsaReefer]

I try to keep an open mind, as well as will give credit where it's due, and Bob Goemans deserves a lot of credit for his contributions to this hobby. But he lost me as a reader of his work back in 2003 after he wrote a glowing product review that tried to "explain the science" behind the infamous snake oil product, the "Eco Aqualizer". After that, when Bob writes a "theory" it's a bit hard for me to take it for face value. Now does this mean he's wrong this time, no it doesn't prove that, but what it does mean for me is I'll wait until I see someone else publish a paper that supports his theory, as I don't really have the time or education to dig into this myself. And I don't find Bob a source I'm willing to trust on face value.

 

[Paul B]

Tulsa, I also do not agree with Bob on everything and I don't even know what an Eco Aqualizer is.
I know Bob and he has been to my home even though he lives in Arizona and I am in NY.
I do know that he has been in the hobby a little longer than me and he is the only person I know that has.
Along the way he has had to have learned at least a little more than many people on here. I myself have written things in articles years ago that I don't agree with anymore.
You have to take every article you read with a grain of salt and try to figure out from your own experiences if it seems plausable.
The problem with these theories and this hobby in general is that are more variables than there are people.
I run a RUGF. Would you try to get someone to do that?

 

[TulsaReefer]

Agreed. I guess my perspective is this, I am not a scientist, I'm an engineer. If I write something outside my profession and education it's as a hobbyist. From my perspective, Bob is the same since he isn't a scientist either, so he falls in the same class as myself, a hobbyist, though with long set of experiences. What I'm saying is that while he may be absolutely correct, I look forward to someone who is a scientist, who can properly work through the science involved, and can then properly take that theory and have it peer reviewed, or at least published in a journal that does review before I take too much stock in it. And I hope someone will take up Bob's theory and work it through a more formal process. It would be interesting to see another view on this topic other than a hobbyist viewpoint.

 

[luther1200]

<a href=showthread.php?s=&postid=14608983#post14608983 target=_blank>Originally posted</a> by superedge88
I can't help but chuckle, are we really trying to equate our aquariums to the ocean? Trying to dissect what kind of sandbeds are in the ocean as if that is what we should mimmic because then our aquariums would "work" right. The ocean has millions of other factors (the largest one being dillution of most of the things we are trying to avoid like nitrate) and to back that up the ocean has some of the most thriving examples of photosynthetic organisms in the world to act as a back up for consuming nitrate/phosphate etc. So to start a conversation about "the ocean isn't bare bottom so our tanks shouldn't be" or "I use coral rubble because that is what the ocean has" from the standpoint of water quality, it is pretty pointless.

THANK YOU, I was glad somebody said it before I got to the end.

 

[luther1200]

Just to start I am not a DSB fan either. But I would think a finer sand would be better. A larger grain would allow more setritus to build up and cause the DSB to "foul" faster IMO. So maybe a larger grain would work better at first, but unless you did frequent WC to clean it with gravel vac you would get more build up, IMO. With a finer sand it can be more easily circulated into the system with water movement, As it will sit on the top of the sand longer.

On another note I think most people have nitrate problems because of overstocking, and over feeding. There is only so much the bacteria on LR and LS can do in a finite area. That is why I believe RDSB work for some people.

 

[Aquarist007]

<a href=showthread.php?s=&postid=14609899#post14609899 target=_blank>Originally posted</a> by Paul B


Capn, Bob seems to think from his research or more likely, the research of the people he quotes that this problem with the anerobic bacteria in deeper areas where there is almost no oxygen at all harbors bacteria slightly different from the anerobic bacteria we have always known about that just turn nitrate into nitrogen gas which disapates out of the water. This other bacteria convert the nitrogen gas back again into ammonium which the shallower bacteria again convert back into nitrates.

anerobic bacteria in deep areas where there is no oygen--to my limited understanding this is a false statement in that one part negates the other. Anerobic bacteria can't live in areas devoid of oxygen--only anoxic bacteria which breat down the nitrates to nitrogen gas????

 

[Aquarist007]

We need somebody like Greenbean or Randy to jump in here

 

[tmz]

The sand bed debate will go on and on and on.There are thousands of pages on it.
Personally, I've tried a number of variations. I have observed many tanks with deep sand beds 4 plus inches with healthy bioloads and near 0 nitrates. I removed a deep sand bed from part of my system and observed a rise in nitrates. Tried remote unlit sand beds too and find them particularly useless,in my experience. Others have noted success with them.

I prefer a shallow bed from a maintenance and aesthetic( I like a beachy look)perspective unless I'm keeping creatures that need more sand, such as certain fish, anemones and corals like sea pens.. All the variations should work with proper care and attention.

If you keep a large fish population and feed them well, you will likely at some point have an issue with nitrate and phosphate, no matter which way you go with your substrate choice. It's just how it is. Refugia with macro algae can help. A sulfur denitrator will do wonders for nitrate. Gfo can control phosphate.Ozone ,carbon,aggressive skimming ,live rock and yes even water changes can help you get it under control and keep it there.

Somewhere,in the explanation of ammonium production a claim to a new theory has risen. It just ain't so and it ain't new , in my opinion. In fact the recommendation for a plenum in the article is really old school.

I believe their are some inaccuracies stated above as well. For example: as far as I know, the only organisms to fix free nitrogen gas are cyanobacteria and their cousins like chloroplasts. All of these photosynthetic organisms rely on anoxic sacs(heterocycts) within their structures to produce and use a unique substance(nitrogenase) which enables the fixing of free nitrogen back into organic forms. I do not believe the creation of ammonium from nitrate and hydrogen has anything to do with this and can't imagine photosynthesis occurring in the dark depths of a sandbed.

In my opinion, folks should plan an aquairum based on what they wan't to keep in it . Substrate, should follow the same path. Deep, bare, etc; less or more live rock, can all work in sync with the rest of the system and system supports if you are keeping larger bioloads (such as gfo, carbon, nitrate reactors and so on).Frequent measurements of critical parameters including phoshate and nitrate will tell you when you have to make a change and there are many options to choose from when you do.

 

[Gravesj1s]

Hmmmm, I dont think NO3- is so much as an issue as PO4 has a real potential to become a problem .
The Goemans article is misleading and flawed.
-Graves

 

[tmz]

<a href=showthread.php?s=&postid=14613292#post14613292 target=_blank>Originally posted</a> by Gravesj1s
Hmmmm, I dont think NO3- is so much as an issue as PO4 has a real potential to become a problem .
The Goemans article is misleading and flawed.
-Graves

High phosphate will interfere with calcium carbonate precipitation. This impairs the coral's ability to calcify and throws it out of balance. High phosphate can quickly harm corals, particularly sps. It will also fuel nuisance algae.It is a limiting factor for green algaes including nuisance algaes such as derbasia and bryopsis. So keeping it very low ( under 0.1 ppm) will limit their growth.

Nitrate can be a problem at higher levels ( above 30ppm in my experience) . It drives zooxanthelae growth which can also be harmful to corals . Some types more than others. I have noticed in my experience that montipora, seriatopora and stylopora do poorly in high nitrates and quite well in near 0 nitrate water. Leather corals seem to like the extra nitrogen source. It will also fuel nuisance algae growth

 

[Joe Pusdesris]

The idea of nitrogen fixation occurring deep in a sandbed is quite interesting. I had thought the majority of fixation in the reef took took place because of cyanobacteria, but this makes sense. Fixation takes place in soil, so why not sand. Fixating diatomic nitrogen takes a lot of energy. In an area devoid of light, the bacteria would need an alternate energy source to fixate nitrogen, say organic carbon. This may be why VSV with deep sand beds prove to be problematic.

Algae and fishfoods also contain energy in the form of organic carbon. Given the information provided earlier in the thread, it would seem important to ensure there are enough organisms to use up the majority of energy in these foods rather than letting it feed bacteria in the sand bed. This may be why sand beds with a lot of worms tend to yield better results than those without.

I myself, am a fan of sandbeds. Only because sand is so much cheaper than rock and serves a similar role in the aquarium.

 

[tmz]

I think the bacteria in a deep sand bed devoid of oxygen would turn to sulfate creating hydrogen sulfide as the concern with carbon dosing and dsbs.

 

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14616267#post14616267 target=_blank>Originally posted</a> by tmz
I think the bacteria in a deep sand bed devoid of oxygen would turn to sulfate creating hydrogen sulfide as the concern with carbon dosing and dsbs.

Yes, providing they were oxygen limited rather than nitrogen limited.

 

[Aquarist007]

<a href=showthread.php?s=&postid=14616267#post14616267 target=_blank>Originally posted</a> by tmz
I think the bacteria in a deep sand bed devoid of oxygen would turn to sulfate creating hydrogen sulfide as the concern with carbon dosing and dsbs.

I thought this condition(deep sand bed devoid of oxygen) supported the growth of anoxic bacteria--the nitrate reducers?

 

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14616649#post14616649 target=_blank>Originally posted</a> by capn_hylinur
I thought this condition(deep sand bed devoid of oxygen) supported the growth of anoxic bacteria--the nitrate reducers?

When they run out of oxygen, they strip the oxygen off of nitrate (NO3). When they run out of nitrate, they strip the oxygen from suflate (SO4), then carbon dioxide (CO2).

 

[Gravesj1s]

<a href=showthread.php?s=&postid=14614296#post14614296 target=_blank>Originally posted</a> by tmz
High phosphate will interfere with calcium carbonate precipitation. This impairs the coral's ability to calcify and throws it out of balance. High phosphate can quickly harm corals, particularly sps. It will also fuel nuisance algae.It is a limiting factor for green algaes including nuisance algaes such as derbasia and bryopsis. So keeping it very low ( under 0.1 ppm) will limit their growth.

Nitrate can be a problem at higher levels ( above 30ppm in my experience) . It drives zooxanthelae growth which can also be harmful to corals . Some types more than others. I have noticed in my experience that montipora, seriatopora and stylopora do poorly in high nitrates and quite well in near 0 nitrate water. Leather corals seem to like the extra nitrogen source. It will also fuel nuisance algae growth

tmz hi , I think maybe I was a bit vague in my post you qouted. I meant PO4 is more of an issue than No3 in deep sand beds.
I still think the Goemans article is misleading....give it a few months and he will be promoting a product to reduce Ammonium.
-Graves

 

[Aquarist007]

<a href=showthread.php?s=&postid=14616802#post14616802 target=_blank>Originally posted</a> by Joe Pusdesris
When they run out of oxygen, they strip the oxygen off of nitrate (NO3). When they run out of nitrate, they strip the oxygen from suflate (SO4), then carbon dioxide (CO2).

tell us more Joe--you seem to be in the know here:smokin:

this is good isn't it?
if they strip the oxygen away from the nitrates---isn't that their purpose--thus reducing nitrates to nitrogen gas??

 

[jenglish]

If these nitrogen fixing bacteria are present in no oxygen zones, it is still not creating any more nitrogen in the system than if the sand was not in the system. The DSB would not be bringing more nitrogen into the system, but this could explain some of the nitrogen cycling back into the system, but only some IMO

 

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14617500#post14617500 target=_blank>Originally posted</a> by capn_hylinur
tell us more Joe--you seem to be in the know here:smokin:

this is good isn't it?
if they strip the oxygen away from the nitrates---isn't that their purpose--thus reducing nitrates to nitrogen gas??

Yes, that's the idea. The statement made to start this thread though is that in the depths of a sandbed without oxygen an enzyme like Nitrogenase can be sustained. (Oxygen breaks down the enzyme) Such enzymes are catalysts in the process of converting nitrogen gas to ammonia.

If these nitrogen fixing bacteria are present in no oxygen zones, it is still not creating any more nitrogen in the system than if the sand was not in the system. The DSB would not be bringing more nitrogen into the system, but this could explain some of the nitrogen cycling back into the system, but only some IMO

Valid point. The thing you are missing is that nitrogen gas is soluble in seawater. In fact, it is more soluble than oxygen, and there is almost nothing that uses it up (Except nitrogen fixators like cyanobactera and bacteria being discussed now), where almost everything in the system uses oxygen. Considering how much oxygen can reach the sandbed, you can deduce that much more nitrogen gas can make it's way down there. So it is possible that nitrogen gas which dissolved in the water from the atmosphere makes it down into the sand bed, thus increasing net nitrogen.