Quote:
|
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.