# Coil Denitrifier



## Lemeshianos (Jan 30, 2008)

What is your opinion on the use of a coil denitrifier for a reef system?

It can reduce water changes by keeping nitrates low. It could take 3-12 months to make a difference in the levels of nitrates though.

What makes me wonder about this device is that its loaded with bioballs and/or sponges and one of the first thing I learned is that these stuff are considered nitrates factories.

So how can a material that accumulates nitrates, and is consider bad for a reed aquarium, be able to reduce nitrates when used in a coil denitrifier?


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## Pasfur (Mar 29, 2008)

An oversimplification...
In your standard biological filter, you create a high oxygen environment to support the growth of nitrifying bacteria. In contrast, for denitrification, you create a low oxygen environment, which promotes the growth of bacteria that convert Nitrate into Nitrogen Gas. 

Most reef aquarists achieve denitrification by using a deep layer of aragonite sand as the substrate.


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## Lemeshianos (Jan 30, 2008)

Further reading on this subject showed that aquariums that base their denitrification on a machine could die in 24 hours if something goes wrong.

A guy had his reef completely dead in 24.
Using such a device will probably reduce the amound of denitrifing bacteria that develop in the sand bend so when the machine is out, you don't have anything to reduce nitrates.


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## Pasfur (Mar 29, 2008)

It is not the buildup of NItrates in such systems that causes an overnight dieoff. It is the release of hydrogen sulfide. Like any piece of equipment, it must be properly maintained. Nonetheless, i see no reason for it. I am an avid believer in a deep sand bed.


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## Lemeshianos (Jan 30, 2008)

Pasfur I've found 2 kinds of Denitrifiers. The coil one just pumps water through the coil ate a very slow rate, then the water goes up a tube filled with biomaterial and then drips in the tank. 

Now the reason for the die off is the following as I have read and understoon in another forum.
The very slow flow of the water is because of the bacteria developed in those biomaterial can't survive when there is regular or even slow flow.
Those bacteria are the same or do the same work as the bacteria in a deep sand bed. Having a denitrifier stops bacteria from being developed in the sand bed. So when you remove the denitrifier you have a sand bed that doesn't have enough bacteria to handle the load of nitrates.
:roll: 
Well I don't know if I have understood correctly. Based on your experience is the above senario plausible or could it just be nonsence?


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## SKAustin (Aug 1, 2006)

I'm going to side with Pasfur here, no need for a coil denitrifiers. There's a better way to accomplish denitrification in a marine system.


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## Lemeshianos (Jan 30, 2008)

Yes, I agree. Its too risky to use one and it takes a long time to start making a difference.


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## Pasfur (Mar 29, 2008)

Lemeshianos said:


> Pasfur I've found 2 kinds of Denitrifiers. The coil one just pumps water through the coil ate a very slow rate, then the water goes up a tube filled with biomaterial and then drips in the tank.
> 
> Now the reason for the die off is the following as I have read and understoon in another forum.
> The very slow flow of the water is because of the bacteria developed in those biomaterial can't survive when there is regular or even slow flow.
> ...


I don't see how this explanation is possible, unless the system is drastically overpopulated. Nitrate is not absorbed and then released again into the system. Nitrate is chemically changed, into Nitrogen Gas, which leaves the system naturally.

Regardless, i can't imagine why you would use a denitrification unit anyhow.


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## Lemeshianos (Jan 30, 2008)

Well from my understanding, the DSB is what turns the nitrages to nitrogen gas right?
So by having a denitrifier that means there is less nitrates for the bacteria in the DSB to feed on. Less food = less population.
So take away the denitrifier and the DSB you are left with no means of nitrates reduction. If the tank is lets say fully stocked. Wouldn't there be a spike in nitrates?Maybe not overnight by within a week?


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