Nitrate in the aquarium

[Cody Ray]

Just wanting to discuss the different ways of removing nitrate from the aquarium. As far as I know there are only 3 ways of removing nitrate.

1. Denitrification (including liverock, DSB, and other bacteria cultivating substrates).

2. Algae cultivation and removal

3. Sulfa reactor

I have also heard of nitrate removal media however I have no personal experience with this and really have not heard anything about it. If you have some solid info on it please share.

As far as I am concerned Denitrification is the most inefficient way of removing nitrate from the aquarium. Denitrifying bacteria located within liverock and in sand beds are not as effective as their nitrifying cousins and there for leaves excess nitrate inside liverock and in sandbeds. This is why IMO people tend to have issues with tank crashes and algae blooms several years after being set up. The rock and sand are no longer able to absorb the unused nitrate that is not used for denitrification. As the bacteria use nitrate this creates something similar to reverse osmosis where water is drawn into the rock slowly. This is however just my opinion but it does help to explain why tanks eventually crash. This would also explain why bioballs and similar equipment are called nitrate factories. The plastic balls cannot hold nitrate that is not used therefor the remaining is left in the water column.

Algae is probably my favorite way of removing nitrate from the aquarium because it is used to grow. That growth can then be removed from the aquarium

I know pretty much nothing about sulfa reactors. If someone would like to add info on this that would be great.

Please feel free to comment (and not to be rude). If you disagree or know something that would add to the thread please comment in a polite and constructive manner.

 

[moumda]

One more method that is probabl;y less effective than the ones you've mentioned is water changes. Another is the dsb in a bucket. I'm currently using this method. It's only been set up for a month and it's knocked my nitrates in half. I've got hopes for better but only time will tell.

 

[billsreef]

Dr. Tim Hovenac recently spoke at my local club on the subject of bacteria in tanks. He had some interesting discoveries on the subject of LR. There was no, yes no, bacteria in the core of the rocks. The theory of bacterial denitrification in the core of LR turns out to be one of those aquarium myths. From talking to Tim Hovenac, it seems most likely that he nitrate reduction we all saw from adding LR and yanking out our bio balls back in the day has to do with all the various algae on the rock surfaces assimilating the N. So growing algae is definitely a great way to reduce N loading in your tank, and it also helps reduce P.

Sulfur denitrators are interesting. They work, but they also increase the sulfate levels in the tank water. So you want to keep up with your water changes to keep the sulfates down.

 

[Luis A M]

<a href=showthread.php?s=&postid=10270039#post10270039 target=_blank>Originally posted</a> by billsreef
Dr. Tim Hovenac recently spoke at my local club on the subject of bacteria in tanks. He had some interesting discoveries on the subject of LR. There was no, yes no, bacteria in the core of the rocks. The theory of bacterial denitrification in the core of LR turns out to be one of those aquarium myths. From talking to Tim Hovenac, it seems most likely that he nitrate reduction we all saw from adding LR and yanking out our bio balls back in the day has to do with all the various algae on the rock surfaces assimilating the N. So growing algae is definitely a great way to reduce N loading in your tank, and it also helps reduce P.

Sulfur denitrators are interesting. They work, but they also increase the sulfate levels in the tank water. So you want to keep up with your water changes to keep the sulfates down.

Interesting,Bill,so another myth is bustered!
We have plenums,NO2 toxicity,hydroids coming in bs eggs...
Hard to imagine sterile drilling to collect samples!:eek1:
How DSB in buckets or in tanks floors remain considered?
And how the LR replacing bioballs in sumps stay?.Aren´t they basically both the same,a substrate for biofilm attachement?.
If this proves true,it could change drastically reef current theories.
Though he could have a technical error and his conclusion be wrong?

 

[Cody Ray]

<a href=showthread.php?s=&postid=10270039#post10270039 target=_blank>Originally posted</a> by billsreef
Dr. Tim Hovenac recently spoke at my local club on the subject of bacteria in tanks. He had some interesting discoveries on the subject of LR. There was no, yes no, bacteria in the core of the rocks. The theory of bacterial denitrification in the core of LR turns out to be one of those aquarium myths. From talking to Tim Hovenac, it seems most likely that he nitrate reduction we all saw from adding LR and yanking out our bio balls back in the day has to do with all the various algae on the rock surfaces assimilating the N. So growing algae is definitely a great way to reduce N loading in your tank, and it also helps reduce P.

I think I have seen something similar to that but I wasn't 100% sure whether it was a real study or just smoke&mirrors. If that is true than it would seem that bioballs along with a refugium filled with algae woud work even better than liverock. Probably cheaper too. No point in spending all that money on liverock if all your paying for is algae. I'm also a firm believer that liverock is great at trapping detritus. Even with tons of flow my rock will release tons of detritus if I blow on it with a turkey baster.

 

[billsreef]

<a href=showthread.php?s=&postid=10272171#post10272171 target=_blank>Originally posted</a> by Luis A M
Interesting,Bill,so another myth is bustered!
We have plenums,NO2 toxicity,hydroids coming in bs eggs...
Hard to imagine sterile drilling to collect samples!:eek1:
How DSB in buckets or in tanks floors remain considered?
And how the LR replacing bioballs in sumps stay?.Aren´t they basically both the same,a substrate for biofilm attachement?.
If this proves true,it could change drastically reef current theories.
Though he could have a technical error and his conclusion be wrong?

Luis, it was really quite interesting. If his sampling was contaminated with stuff from the surface, he would have found bacteria, just not the ones he was looking for. In this case he found a complete absence of bacteria. Of course there is room for doubt in any scientific study, but it certainly made me think. I've long thought the real magic to nitrate removal by LR was really assimilation by the abundant algae that's found even on "clean" rock. While he hasn't done the research to prove that concept, it does seem logical. While biofilms for transforming ammonia to nitrate can occur on any surface, be bio balls, bio wheels, or rock, I find LR to have benefits of biodiversity that always seem to make a tank run better that you don't get using bio balls and such.

 

[wooden_reefer]

<a href=showthread.php?s=&postid=10270039#post10270039 target=_blank>Originally posted</a> by billsreef
Dr. Tim Hovenac recently spoke at my local club on the subject of bacteria in tanks. He had some interesting discoveries on the subject of LR. There was no, yes no, bacteria in the core of the rocks. The theory of bacterial denitrification in the core of LR turns out to be one of those aquarium myths. From talking to Tim Hovenac, it seems most likely that he nitrate reduction we all saw from adding LR and yanking out our bio balls back in the day has to do with all the various algae on the rock surfaces assimilating the N. So growing algae is definitely a great way to reduce N loading in your tank, and it also helps reduce P.

What does he mean by the core of the rock? Are there not deep crevices in LR? Can the deep crevices be anerobic enough to be sites of denitrification?

 

["Umm fish?"]

I always thought the best benefit to live rock was all of the small creatures and their ability to reduce food particle size quickly down to something that bacteria can handle efficiently. Can't get that with bioballs.

 

[wooden_reefer]

<a href=showthread.php?s=&postid=10275410#post10275410 target=_blank>Originally posted</a> by "Umm, fish?"
I always thought the best benefit to live rock was all of the small creatures and their ability to reduce food particle size quickly down to something that bacteria can handle efficiently. Can't get that with bioballs.

The curing process will kill many creatures in live rock. Many people use the dead creature as ammonina source to cycle the tank.

When I first heard of this, I felt that the whole idea was absurd. I mean the idea of spending a few hundred bucks on biological filter medium just seems lunacy to me.

Then I know that many people report much lower than expected nitrate level from LR as biological filter medium.

I am not going to use LR as biological filter. I will set up separate nitrification and denitrification. I think the more knowlegable an aquarist is, the more he/she will shun LR as a biological filter medium. Just my opinion.

 

[Cody Ray]

That is a very interesting comment. I would like to hear more about your idea.

 

[tperk9784]

<a href=showthread.php?s=&postid=10279735#post10279735 target=_blank>Originally posted</a> by wooden_reefer


I am not going to use LR as biological filter. I will set up separate nitrification and denitrification. I think the more knowlegable an aquarist is, the more he/she will shun LR as a biological filter medium. Just my opinion.

I would also like to hear more about what you intend to do. Do you plan on having no live rock at all in your tank? How do you plan on setting up these different "zones"? Why should people shun live rock?

 

["Umm fish?"]

The curing process will kill many creatures in live rock.

Yes. And the rest expand their population and fill your live rock and, with some of them, your sandbed.

 

[billsreef]

<a href=showthread.php?s=&postid=10279735#post10279735 target=_blank>Originally posted</a> by wooden_reefer
I think the more knowlegable an aquarist is, the more he/she will shun LR as a biological filter medium. Just my opinion.

If all you're looking for is strictly a traditional bio filter to transform ammonia to nitrate, than yes other media is going to be more economical. However, for reef tank or even a fish tank, there are far more benefits to using LR. Among other things, there is lots of algae on LR, not just coralline either. Even rock in a tank without any nuisance algae problems has an abundance of algae growing on the surfaces. This algae readily and rapidly assimilates ammonia, before it can even be transfered to nitrate. There are whole host of other beneficial organisms as well. I've been in this hobby since the box filter was considered state of the art. Used every sort of filtration you can think of over the years. LR has done more for tank stability than any other form of filtration going. I wouldn't dream of setting up a tank, even a fish only, without it

 

[BeanAnimal]

Good thread... I have long scoffed at the "embedded" bio filter that people claim LR to hold. I have always thought that the surface area was a benefit, as with any other media. I always had these thoughts, and the various "cooking rock" threads cemented the idea. The more I read about rock cooking, the more I think it is silly.

I would agree that LR is usefull and does play an important role in a balanced setup. The more porous the rock, the more surface area it has to hold the surface bacteria and/or algae and other organisms.

 

[wooden_reefer]

"Even rock in a tank without any nuisance algae problems has an abundance of algae growing on the surfaces. This algae readily and rapidly assimilates ammonia, before it can even be transfered to nitrate."

If you are saying that the surface physical structure (smallness of crevices, extended surface area per unit mass etc) of the "live rock" is the major factor, I would tend to agree. I would even have to agree if you say that the chemical composition of the liverock promotes a richer growth of all sort of organism that promote tank health, I'd also agree. But I don't think this is the suggestion.

Otherwise, what is liverock? Can there ever be dead rock? All rock is liverock after a few months. To me, liverock is rock which is collected from the ocean.

Suppose you can make rock that has the same surface phyical structure (may be also chemical composition) as liverock collected, then why would you need much liverock. OK I would agree that a few pounds of such liverock should be included as seeds of all sort of micros and creatures. When a suitable ebvironment is created, they will populate it.

Why can't you have deliberate nitrification and denitrifixcation? Why can't you create much surface for the growth of suitable algae for active consumption of your cleaning crew without liverock?

 

["Umm fish?"]

OK I would agree that a few pounds of such liverock should be included as seeds of all sort of micros and creatures.

More rock = more possibility of diversity, would be my argument. Even better, more rock from as diverse origins as you can find.

 

[wooden_reefer]

I don't think you would have much more diversity if the rock is collected in about the same locale. If it is not, then it is diversity that was never used.

Would a random sample of 10,000 people in LA has detectably more diversity than 100,000 people also randomly sampled?

 

[wooden_reefer]

Moreover, I tend to think that there is a difference between using LR as the biological filter medium and cycling a tank with LR.

In cycling with LR, the LR is placed in an uncycled tank and the ammonia from dead organisms in the LR is used as the source of ammonia. I simply ask this question: for how much longer would the remaining live organisms have to live in high ammonia concentration? Do you not think that there is a good chance that the ammonia would kill some organisms? Are there any organisms known to science other than nitrification bacteria that needs ammonia and nitrite? Wouldn't longer exposure to ammonia reduce "diversity" further?

I think cycling with LR is a rather absurd concept.

I believe that if one is going to use LR as the biological filter, one should place it in a cycled tank. And be very patient. Even in a cycled tank, nitrification bateria will still grow on suitable and unpopulated media; just that it will take a while. One should put up with the nitrate factory of power filter for a while and gradually allow the LR to become biological filter. IMO

 

[Cody Ray]

I still have a question. If there are no appriciable populations of denitrifying bacteria inside liverock then why are we as hobbiest buying soo much when what we are really wanting is the flora and fana that lives on the outside? It would indeed be more friendly money wise and to the enviroment to buy a small portion of rock and allow it to colonize new rock. Even better use small amounts of liverock and dry sand along with plenty of macro algae. I have always had better sucess with macro algae in either the tank itself or in a refugium.

 

[wooden_reefer]

<a href=showthread.php?s=&postid=10281569#post10281569 target=_blank>Originally posted</a> by crrichey
I still have a question. If there are no appriciable populations of denitrifying bacteria inside liverock then why are we as hobbiest buying soo much when what we are really wanting is the flora and fana that lives on the outside? It would indeed be more friendly money wise and to the enviroment to buy a small portion of rock and allow it to colonize new rock. Even better use small amounts of liverock and dry sand along with plenty of macro algae. I have always had better sucess with macro algae in either the tank itself or in a refugium.

I think the suggestion is that there is tremendous surface area on LR for algae and the cleaning crew like this type of algae.

This is possible. Many animals like new growth in grass. They may not eat old grass. The same can be true for fish and snail etc. They may more readily eat very short filament algae on the LR crevices because the texture and taste to them may be different than the long filament on glass etc. I won't dismiss this possibility quickly.