Dnitrification Via Live Rock. Maybe

[florida joe]

I see more and more posts telling new hobbyists and old to add more live rock into their tanks if they have a nitrate problem. But lets look at it. Why live rock? It is a median where anaerobic bacteria can colonize within.
But all live rock is not born equal. Porosity is the major factor. The speed at which the water passes through the rock through advection determines if we have a breeding area for the anaerobic bacteria. That pretty live rock with all that coraline algae on it that we pay so much for may be totally devoid of denitrifying bacteria. For that matter it may not even have any nitrifying bacteria on it. You just don’t know for sure.
My LFS has large tanks of live rock. Now lets assume when he gets his shipment of live rock from what ever sources that may be, it can accomplish denitrification. Is his introducing enough ammonia to sustain denitrification? The LFS may sell higher forms of algae, which will limit the amount of nitrates in the water as most tanks in local fish stores are interconnected, this lack of nitrates will in face starve the anaerobic bacteria.
The new hobbyist and old with the nitrate problem is constantly told if you have nitrates add live rock. He or she goes out spends their money on beautiful looking live rock, puts it in there tank and testes for nitrates. Is it possible what when they test for nitrates the levels are higher? They do not know if in fact there is any anaerobic activity within the rock. What they do know with a one hundred present certainty is that they have displaced water. Less water less dilution of the nitrates in there tanks. Which will show up in a higher nitrate reading oh my oh my.
I am not saying live rock is not a platform for denitrification. Or a good one. What I am saying however is that the development of anaerobic bacteria with in live rock if it is going to happen is a slow process and once that development takes place the denitrification within is a slow process.
As we all know marine hobbyists are not the most patient people in the world and I can see how after the introduction of live rock, the great expectations for denitrification they were told to expect may not come true.
These are just my own personal thoughts.
Lets discuses the issue my friends

 

[mr_x]

this is the first time i've heard to add more live rock if you have elevated nitrates. i was always taught to find the source of the nitrates and correct the issue that way.
meanwhile, if you have nitrate problems, i'd say you have nutrient rich water capable of sustaining bacteria. adding new live rock, with or without bacteria, is simply like you said- adding more surface area. i believe this rock will be colonized with bacteria soon enough, if in fact it's void of it.

 

[naclh2o nut]

I am in agreement here. The only thing we as R/K can do to adjust nitrates quickly is a h20 change. Like I have heard you say for many months -dilution. But is the addition of rock probably the long term solution? IMO there is a balance that we must achieve with gal(h20) / lbs(l/r), problem is what is that number.

What we need here is an idea of how long it and what ratio people have in there tanks, when they reached 0 nitrates with out h20 changes.

That would be something to know, but am willing to bet now one has. Addition of fish/ coral adding to bio load. H20 changes for trace replacement, etc.. But it would be nice to know!

I am tagging along for this ride, Joe is the thread starter.

 

[florida joe]

Originally Posted by Mr_X
http:///forum/post/2956036
this is the first time i've heard to add more live rock if you have elevated nitrates. i was always taught to find the source of the nitrates and correct the issue that way.
meanwhile, if you have nitrate problems, i'd say you have nutrient rich water capable of sustaining bacteria. adding new live rock, with or without bacteria, is simply like you said- adding more surface area. i believe this rock will be colonized with bacteria soon enough, if in fact it's void of it.
My friend I can assure you if you and I had a dollar for every suggestion to add live rock to combat nitrates we were be very rich.
The added surface area of live rock will colonize bacteria. The bacteria, which convert ammonia to nitrate. The anaerobic bacteria that colonizes within the rock needed for denitrification is slow materializing if at all And if materialized the progression from water advection to denitrification is a slow process

 

[mr_x]

Originally Posted by florida joe
http:///forum/post/2956054
The anaerobic bacteria that colonizes within the rock needed for denitrification is slow materializing if at all
how do you know this to be true?

 

[spanko]

So then does this open by Joe lead us to the fact, yes I would argue that it is a fact, that rocks are the dreaded nitrate factories that we accuse bio media of being?
To me the rock works job in biofiltration is to lend more surface area to the tank in an effort to make homes for the bacteria needed for the biofiltration. However as Joe has pointed out the homes created may not be targeted to the denitrifying bacteria and by definition may in fact be lending themselves go being home to nitrate producing bacteria. A good thing indeed, just as bio media is a good thing when used for its intended purpose and maintained as needed.
The hobby experts have been developing over the years ways to reduce nitrate, and for that matter phosphate but that is another discussion, in our tanks. Zeovit, Prodibio, Brightwell Products, Plenums, DSB's, Algae Scrubbers, Protein Skimmers, Refugiums with macro algae that are harvested regularly, and on and on.
New and experienced aquarists need to recognize, IMO, that they addition of live rock to the system helps to create homes for aerobic bacteria in great quantities but may not do enough to provide for anaerobic to make a large difference.
For those aquarists not knowledgeable enough, confident enough, or with the desire to invest heavily in some of the nitrate reduction products - processes I would submit that a proactive water change schedule is still a good way to remove - dilute nitrates from the system.
Again Joe's original question is centered on nitrate removal. Nitrate in some level being good or bad for the system is another discussion. Fun stuff Joe, let the posts roll in!!!!

 

[florida joe]

Originally Posted by Mr_X
http:///forum/post/2956056
how do you know this to be true?
Good question. A few years ago at a saltwater seminar. The live rock anaerobic bacteria discussion points out that the black areas with in the rock were the sites of anaerobic bacteria. Some time later I decided to break a large piece of live rock into a few smaller rocks and was surprised at how little black area was present. I added that rock back to my tank. A few months later just for the hell of it I took one piece of the previously broken rock out a once again broke it. Very little if any no black areas were present.
THIS WAS NOT a controlled scientific experemt just something I did on my own. And I present it as such.
Now if we do go by the acknowledged way denitrifying bacteria are formed within rock we see that the process of water at need zero oxygen levels passing through the rock via advection is a slow prosses if for no other reason then the density of the rock

 

[mr_x]

Originally Posted by florida joe
http:///forum/post/2956069
The live rock anaerobic bacteria discussion points out that the black areas with in the rock were the sites of anaerobic bacteria.
i'm not disputing this as fiction, but the masses can be wrong. a perfect example of that would be the pectinia coral. every website you go to lists it as SPS. i believe one made that mistake, and everyone else copied and pasted the info.
the same could be about these "black areas". does anyone know where i coudl find scientific studies about this?

 

[florida joe]

Ok lets assume anaerobic bacteria colonizes as fast as nitrifying bacteria. If that was true we should never have a nitrite problem as we establish nitrification we introduce nitrates, the food for development of anaerobic bacteria. The more nitrates the more food for anaerobic bacteria to develop I just don’t see how the imbalance between nitrification and denitrification can be present with out the development of the anaerobic bacteria being much slower. And this imbalance is evident with constant chronic high nitrates

 

[spanko]

I can't make that correlation Joe. I am not sure growth rate is the issue as much as area of reduced oxygen levels where the bacteria grow.

 

[kube]

so what you are saying if the bacteria that breaks down nitrate most grow slower that the bacteria that converts ammonia into the final product of nitrate, because it they were the same growth rate then we would never have a nitrate problem, thus trying to justify your believe that the bacteria that breaks down nitrates grows slower
and to the point of this topic you are trying to say that by adding more rock it is quickly colonized by the bacteria that breaks down ammonia thus creating more nitrates while the hobbyist waits for the bacteria that breaks down nitrate to slowly colonize the rock and play catch up
valid point and good food for thought, but i'm no expert in this field

 

[florida joe]

Originally Posted by spanko
http:///forum/post/2956084
I can't make that correlation Joe. I am not sure growth rate is the issue as much as area of reduced oxygen levels where the bacteria grow.
Henry I would think the amounts of live rock people put in their tanks would certainly afford them ample areas for anaerobic bacteria. They are also not dealing with the problem of aeration by sand sifters. Consider the radius of a piece of live rock and compare it to a sand bed depth. The live rock should out perform but does it ?

 

[florida joe]

Originally Posted by Kube
http:///forum/post/2956106
so what you are saying if the bacteria that breaks down nitrate most grow slower that the bacteria that converts ammonia into the final product of nitrate, because it they were the same growth rate then we would never have a nitrate problem, thus trying to justify your believe that the bacteria that breaks down nitrates grows slower
and to the point of this topic you are trying to say that by adding more rock it is quickly colonized by the bacteria that breaks down ammonia thus creating more nitrates while the hobbyist waits for the bacteria that breaks down nitrate to slowly colonize the rock and play catch up
valid point and good food for thought, but i'm no expert in this field
We are basically on the same page but
It is not that the live rock is colonizing more nitrification bacteria, because your tank is already cycled. The rate of nitrification is already established. And increased bio load would be needed to facilitate the establishment of added colonies. My reason for the tread is simply to shed light in my opinion that the addition of more live rock to eliminate nitrates may not be the answer

 

[naclh2o nut]

Joe,
Do you mean not the answer at that time, but should help in the future. (Once the rock is colonized) i agree with that and belive that adding L/R could possibly lead to a spike in nitrate. if there was any die off.

 

[geoj]

Because it is idiot proof, and don’t play Devils Avocet with me that’s what I do

and
I have not done any time trials on bacteria growth but I think that the area that can be colonized has ultimate importance as to how much waste can be dealt with in a giving time. So if you are in a hurry to get to a stable cycled tank starting with the area you will need will speed things up.

 

[natclanwy]

Originally Posted by florida joe
http:///forum/post/2956079
Ok lets assume anaerobic bacteria colonizes as fast as nitrifying bacteria. If that was true we should never have a nitrite problem as we establish nitrification we introduce nitrates, the food for development of anaerobic bacteria. The more nitrates the more food for anaerobic bacteria to develop I just don’t see how the imbalance between nitrification and denitrification can be present with out the development of the anaerobic bacteria being much slower. And this imbalance is evident with constant chronic high nitrates
I don't know if the reproduction rates are the same or not but like you said for the sake of this point we will assume that they are. It takes a very specialized environment to support anaerobic bacteria and with certain types of even very low amounts of oxygen are deadly. With that being said the amount of available habitat available to anaerobic bacteria is very low in comparison with aerobic bacteria. This lack of area for anaerobic bacteria to grow IMO could account for the imbalance between nitrification and denitrification.
The development of anaerobic bacteria may hinge more on the available habitat than the reproduction rate, after transporting LR I am guessing a significant portion of the anaerobic areas of the LR are contaminated with oxygen killing off the anaerobic bacteria in those areas, but after being placed in our tanks the aerobic bacteria that have colonized these areas will slowly use up the oxygen available and die and now allowing anaerobic bacteria to colonize those areas again.

 

[saltymarine]

Ummmm, what?

 

[florida joe]

Originally Posted by natclanwy
http:///forum/post/2956602
I don't know if the reproduction rates are the same or not but like you said for the sake of this point we will assume that they are. It takes a very specialized environment to support anaerobic bacteria and with certain types of even very low amounts of oxygen are deadly. With that being said the amount of available habitat available to anaerobic bacteria is very low in comparison with aerobic bacteria. This lack of area for anaerobic bacteria to grow IMO could account for the imbalance between nitrification and denitrification.
The development of anaerobic bacteria may hinge more on the available habitat than the reproduction rate, after transporting LR I am guessing a significant portion of the anaerobic areas of the LR are contaminated with oxygen killing off the anaerobic bacteria in those areas, but after being placed in our tanks the aerobic bacteria that have colonized these areas will slowly use up the oxygen available and die and now allowing anaerobic bacteria to colonize those areas again.
Exactly my point. Adding live rock to eliminate nitrates is not a fast paced answer. Yet many new hobbyist are being told to do just that and they are expecting immediate results

 

[natclanwy]

I agree, its my opinion that it takes 6 months to a year to reap the full benifits of live rock and deep sand beds. It is definetly not a short term solution. Which is one of the reasons I recommend waiting at least six months before you start adding any delicate corals or fish.

 

[florida joe]

Originally Posted by natclanwy
http:///forum/post/2958168
I agree, its my opinion that it takes 6 months to a year to reap the full benifits of live rock and deep sand beds. It is definetly not a short term solution. Which is one of the reasons I recommend waiting at least six months before you start adding any delicate corals or fish.
My friend that is an excellent thread to start. The art of patients