De-Nitrification ColumN - Heard of This?

[newsalt]

While searching the internet for Nitrate removal in aquariums, I stumbled upon this small article on a U-Tube de-nitrification column. Please read it. I've listed a few questions about it after the article.

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Home Made De-Nitrification Column

If the filter cannot be partitioned or you use an internal power filter, you can construct and use a denitrifying column. This consists of a "U" shaped piece of plastic plumbing pipe. The tops are left open and are made 3in higher than the water level. The column is placed next to the aquarium. A piece of airline is placed into one end of the column and an elbow attachment is fitted at the other end, just above the top of the tank level. The column is then filled with a porous filter media, so as to provide as large a surface area as possible. The airline is then fitted/ adapted to fit the outlet of the filter. The filter then forces water down the airline tubing, which in turn passes through the column and returns to the aquarium via the elbow placed over the side of the tank. The water flow is slow and once anaerobic bacteria are established, then denitrification occurs. It should be noted that anaerobic bacteria may not establish as quickly as its aerobic counterpart.

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Has anyone used or heard of theis method for de-nitrification?
My questions are:

1. The"u-tube" pipe, what diameter? Will 1/2" work?
2. The porous filter media it mentions, what kind?
3. It says an airline is fitted to the outlet of the filter. Would tapping into the suction tube of an HOB filter with 1/4" tube work?
4. The info I've read on de-nitrification coils talks about a system that is low in oxygen for it to work right. How is this "u-tube" idea low in Oxygen?

Your thoughts on this article is appreciated.

[Scooterman]

Strange, sounds like a lot of trouble.
It also sounds confusing in the discription, either it will work like LR, or like Bio-Balls, which you don't want in a reef. I think this guy needs to supply more information.

[ScottT1980]

Do you have a link? I tried to google it withotu much luck. I am like Scooter, a bit confused as to how it functionally is working. I would love to see a picture of this thing...

The basic gist that I get it that you cram enough "stuff" into a return from a canister filter or any sort of pump enough to really slow down the flow. It seems touchy, too much flow and you will have an aerobic region while too little flow would almost render it useless (almost no water flow, killing the pump and not denitrifying enough water)...

But, perhaps I am a bit confused. The airline is what is getting me. Is the airline from the canister filter or is it just small airline used for pumps, etc...

Take er easy
Scott T.

[newsalt]

I was able to find the site. Go to:

http://www.marksfish.dipsy.cyberprog...ts/plants5.htm

Scroll down to "Home Made De-Nitrification Column"

[Scooterman]

Fresh water.

[newsalt]

You mean that will only work in a freshwater aquarium?

[sorcerer]

Newsalt here is a link to a DIY de-nitrator coil intended for use with marine aquaria:

http://www.aloha.net/~hqf/indexdondenitrator.htm

and here is a link to a commercial nitrate reductor by aquamedic.

http://www.seaquestmarine.com/cgi-bi...&SEARCH=search

I'm not sure that the u-tube design would work well in saltwater or not. From past discussions, coil de-nitrators can work but are usually difficult to get the flow rate tuned to where it works well. I don't know anyone that has tried the Aquamedic product.

[Scooterman]

Few people would argue that a well planted aquarium provides the perfect backdrop for tropical fish.

I'm not sure about a SW tank, it may work with some modifications but is this really worth doing?

[DaveK]

Originally Posted by newsalt

While searching the internet for Nitrate removal in aquariums, I stumbled upon this small article on a U-Tube de-nitrification column. Please read it. ...
Has anyone used or heard of theis method for de-nitrification?
My questions are:

1. The"u-tube" pipe, what diameter? Will 1/2" work?
2. The porous filter media it mentions, what kind?
3. It says an airline is fitted to the outlet of the filter. Would tapping into the suction tube of an HOB filter with 1/4" tube work?
4. The info I've read on de-nitrification coils talks about a system that is low in oxygen for it to work right. How is this "u-tube" idea low in Oxygen?

Your thoughts on this article is appreciated.

Years ago I built a similar device I use 1 1/2" PVC pipe so that I had a U tube about 4 feet tall. I then filled the U tube with Nitrex. The flow into one side was airline tubeing plumed off the main sump return. The return was 1/2" plastic tubeing. Denitrification requires some sort of food source, and that's why the Nitrex was used. Today there are other products that could be used.

You run water thru such a unit by the drop. 60 to 100 drops per min is about right. As you can see this is a very slow process. It took about 6 weeks before the input water was comming out nitrate free. This kind of filtration requires a lot of checking and adjustment. Too little flow and you get sulfate reduction and the rotten egg smell, too much flow, and you get a nitrite factory.It's realy a pain to use this sort of unit.

Later on I got an Coralife denitrator. Don't bother looking for it online, the company quit makeing them years ago. It worked bu using 5 small roles aof DLS and being fed by their "Ana Food", which I suspect was some sort of sugar based product. The problems with flow control and with feeding the filter, also made it a pain to use.

I also used several other types of denitrators over the years. IMHO they are a lot more trouble than they are worth.

To answer your specific questions -

Denitrators need to be built kind of large, because the process happens slowly. It's done it's job drop by drop. 1/2 tubeing would be way too small. However a denitrator is one device that does work in FW or SW.

The media can be just about anything, but the bacteria need to get food from some place. Sometimes, like with Nitrix, the media is also the food.

Generally with a hang on tank filter, there is no good place to tap into it You need to be on the return side of the pump. Often this is not possible with some hang on tank stuff.

The U tube is low in oxygen because the water goes so slowley through it. The first section usually is aerobic and depletes the oxygen, so its easy for the rest of the U tube to be anaerobic and do the denitrification.

Generally today, I don't recommend denitrators becuase there are much better ways of doing things. Liverock and/or a deep sand bed do a lot more, and are a lot less work.