Aquarium Chemistry: The Nitrogen Cycle: New ...

Aquarium Chemistry: The Nitrogen Cycle: New Developments and New Prospects
So far we have always thought of the nitrogen cycle as a series of linear reactions that conclude in a circle. But is it really a cycle?
By Marco Colasanti
...this knowledge allows us to better understand that which can occur in our tanks and nurture our passion for aquarium.

The Nitrogen Cycle has never been thought of as a singular cycle nor as a linear path that ends in a cycle.

It is, and always has been, a series of interconnecting cycles and linear pathways between those cycles.

I am a little surprised that teh article is hailing this as a "new" development when this has been a message on the forum and in fish keeping general for many decades.

So, the conclusion here is that there is nothing new about the article. BUT.....what is given in that article is not fully correct nor comprehensive either.

ian

ps....I forgot to add (as I was in a hurry at work)....

the linked article is, no matter what, an excellent article and review.

It is infinitely better than any other article that I have seen on the internet within the fish-keeping world.

Generally, I am amazed at how often people will ignore the known and written facts (and the written bits about what is not quite known) that are contained within that article yet prefer to continue to copy-n-paste the same old stuff.

I know myself that when giving and having written pieces on it over the past 30 odd years that so many people do not want to know the facts.
It has also been difficult to explain to keepers that there tanks is NOT "fully cycled" simply because they see a reduction in ammonia and an increase in nitrates, and that assuming such is ignoring the point of true maturation of a tank.

There are some parts of the "cycle" not mentioned (I didn't find them anyway) in the linked piece such as Oxygen-Limited-Autotrophic-Nitrification-Denitrification, or manganese dependent chemodenitrification, or manganate dependant chemoxidattion.
And possible the role of bacteria such as Bacilus subtilis (hay bacteria)

However, I would not necessarily deduct any review points for an author not mentioning them as they are quite limited.

What is, however, one of the key parts of this is something that I was baffled by 30 years ago when doing denitrification experiments in developing new filtration systems..........something did not add up in the calculations in very mature marine tanks with deep anaerobic chambers. Whilst the denitrification in quite immature systems seemed to go as planned, very mature systems simply baffled me and I thought my chemistry theory was well off the mark.
It so happened that others were equally baffled by something missing out of the equations....so something else was suspected.

It wasn't until just over 20 years ago that the solution to those missing bits was directly shown to be another major process: the anaerobic ammonia oxidation pathway (Anammox, as it is called).

It is pleasing to my eyes to see another fish-keeping writer to mention such an important part of the cycle.

Now.....here is, of course, the crunch:
if someone (as JohnH above hinted) doesn't want to get into the science of this then there is no need to as good fish-keeping practice is all that is needed; but if someone does wish to get into the science and mess with water chemistry then article like the linked one are absolutely vital.

ian

Thanks for comments.
As you said ian the article like this are absolutely vital. I see on many forums questions, why fish died in the ne tank after a few days? That`s the answer. Why water is to cloudy... and plenty of the basic similar questions. So, this is for beginners, like me for axample. I had some problems to understand language (not theory) but if I understood, for John, I`m sure, this is piece of cake I`m joking, of course. You right John, is a bit too 'scientific' but good to know this theme from this 'scientific' side as well.

One of the things that I very often say is that I do not like the word "Cycled" (when referring to a tanks maturation) and I hate the term "Fully Cycled".

....and through in the term "the water is perfect"...and that just caps it.

But, because of some nonsensical terminology that has gotten hold within the fish keeping world I even find that I have to use such jargon to keep the conversation within the picture frame.

There is very likely (and I'm not going to count ) more rubbish written on the subject than there is proper info on the subject. The proper info is out there, but most ignore it.

Whilst, without any additions in way of bacteria-in-a-bottle or OrganicAQua or Squeezings, a tank may tank around 6 weeks to get to stage of being suitable for fish with respect to the dealings of ammonia, it is nowhere near "Fully Cycled"....no matter what the standard test results say.

The Anammox part of the cycle tends to take a long time to establish (my findings are that it is somewhere in the region of 9 months to a year before that part is up to speed for a close to maturation stage; others may find different figures).

Another point that is often ignored is what happens when things go wrong.

Discus fish keepers are often the subject of that problem because of the way they have manipulated their water to get it "perfect" (???)........but trying to tell an "I know it all" Discus snob is like getting water out of a stone (even when looking at a tank full of fish with "discus malady" and acidosis)
(by the way, I am not knocking Discus keepers as I am a discus keeper)

I don't think that the linked article went into that.
The author is not a chemist and so ,naturally, probably not look at that side of things.

A very well matured and balanced tank is hard to topple as there are so many pathways at work that if one is knocked out, the other would kick-in to some extent. Nature is fragile but also resilient to some extent.

On the article, as a whole, I do feel that the author is a little naive and possibly quite new to the subject (oh yes I do....if my honest opinion be known).

The opening statement is a bit of an insult to those who have worked on such stuff for decades; it indicates that the author has not really done much work to find out what is known by fish-keepers.

The inclusion of copy-n-paste cartoons (and that is what they are called in the biochemical world)from a biochemical paper/book on the membrane proteins etc is not really needed in such an article though.
They would be great in a monograph on the subject, but not in the context the author was writing.

Little "black boxes" would have been good enough to replace the protein cartoons.

Alas, whether we wish to understand it all or not, the fish are the ones who have to experience the water.

ian