Denitrification coil

[Paul B]

I built this coil a few years ago and it worked well. A de-nitrification coil is a simple device that reduces nitrates to zero for no money and it is a simple design costing maybe $25.00 to build. Hurricane Sandy put an end to the thing as it needs constant water flow and a few days without water flow will make the thing as helpful as some of our rock singers. I have posted the construction before but I will do it again in my book that is not out yet. Basically it is a long tube where anerobic bacteria grow on a diet of nitrates and Vodka. The Vodka keeps them smashed so they don't realize they are working for free. The thing also needs 3 weeks to a month to start working but now it reduces nitrates from 40 (which my reef is) to zero. It is still cycling in my workshop and I will again install it on my tank as soon as I get some time.

The device is just the blue tube, the rest of the stuff is just my normal workshop stuff.

http://i258.photobucket.com/albums/hh270/urchsearch/2014-12-13081858_zps2ac5a22b.jpg (http://s258.photobucket.com/user/urchsearch/media/2014-12-13081858_zps2ac5a22b.jpg.html)

The tube on the right is tank water and the tube on the left is water that leaves the coil.

http://i258.photobucket.com/albums/hh270/urchsearch/2014-12-13081851_zpsa4d9882a.jpg (http://s258.photobucket.com/user/urchsearch/media/2014-12-13081851_zpsa4d9882a.jpg.html)

[skeeter_ca]

I tried a coil denitrator many years ago. I could never get it to do anything. Always had to fiddle with the drip rate. It was only about 12inches tall. Never heard about using vodka with it.

skeeter

[option61c]

In almost 30 year of tank evolution...FO...FOWLR...REEF...I have always used a coil. I'm curious Paul, why did feel you needed to feed it? I've never done it because I never saw the need. The units I've built for myself and friends over years all started producing zero nitrate output at 3-4 weeks.

[vega77]

A good link to a diy build anyone? :)

[AZBigJohn]

Paul, I searched and found your build thread, but all the pictures/sketches of the design are no longer available in that thread (they have moved or been deleted on photobucket).

Any chance you still have them around somewhere. I have to admit to being a more visual person, and the description of what you did is just not helping me to picture it at all.

[Paul B]

Option the last one I built I didn't feed, this one I do, it's just a change of pace and probably doesn't even need it. But this is probably a fifth prototype as I keep tweeking. John the building of the last one was different, this one will be in my book because I don't want to put it out there until I am sure it works correctly and this one is not finished as I want to change a few things as I experiment. It's basically a 50' tube and little else

[Paul B]

The thing finally seems to be cycled and it is working about twice as fast as the original design. This one is the same coil but I added about 5' of sand in a 3/4" pipe. It is processing about one drop a second and so far turns nitrates of about 40 to zero in the 10 minutes or so the water takes to get through the device. I am not going to install it on my tank yet as I still need to do more testing. It has been cycling for one month but I still want to process water faster. The test results are from the water entering the device and coming out.
http://i258.photobucket.com/albums/hh270/urchsearch/2015-01-13145706_zps6c28a18f.jpg (http://s258.photobucket.com/user/urchsearch/media/2015-01-13145706_zps6c28a18f.jpg.html)

[option61c]

Funny you should bring this up again at this particular time. Unfortunately because of health issues, my tank has laid fallow for almost 4 years. After having it run successfully for 20 years I just couldn't seem to gather the will (or strength) to take it down. Right now it's a 55 gal bucket of rocks that had just a pump running to keep it from getting stagnant. It didn't even have a light on it. Now that my daughter is old enough to help we're going to start resurrecting it and building a new coil is on the agenda (among a dozen or so other items).

I'm trying to visualize the pipe with sand in it. Are you using the sand as an anaerobic substrate? I'm guessing that it runs the length of the CD and the output end of the coil goes into the bottom of the sand pipe? The water percolates up through the sand and comes out the top. Do have it right?

If I'm visualizing this correctly, then I think I'd be worried about the sand pipe getting clogged at some point. In my CD's I use good old fashion Bio Balls ($8.99 for a 100 on Amazon) as the substrate. I have found that they provide plenty of surface area and yet provide enough void spaces so that bacterial mats never have a change to close the central column of CD completely. Let me know if I have it right because it does sound interesting.

[EnderG60]

I made a few of those years ago and got them to kinda work. They always ended up clogging and needing to recycle. In general just ended up being a HUGE PITA.

Went to sulfur and never looked back.

[Paul B]

I'm trying to visualize the pipe with sand in it. Are you using the sand as an anaerobic substrate? I'm guessing that it runs the length of the CD and the output end of the coil goes into the bottom of the sand pipe? The water percolates up through the sand and comes out the top. Do have it right?
That is correct. But I made it so that the sand is after the coil and I can remove the sand portion, open it up and easily change the sand. I believe the remaining bacteria in the coil will keep the bacteria going when, and if there is a need to change the sand. But it is an experiment so I really don't know for sure.
EnderG60. that probably will happen eventually and it would need to be cleaned and recycled. I could theoretically do what I just said and because the thing is made in two parts, I can clean the coil or the sand separately while the other part runs. That's my theory anyway and the reason I built it that way