DIY Coil Denitrator Plans

[ncutler]

After reading the entire thread which has helped me enormously. I've decided to do the multiple coil approach.

The one thing that wasn't really discussed that much was the media used. There was mention of Seachem's de-nitrate but it sounds like there really isn't much point to use such media because the amount of surface for the anaerobic bacteria would be sufficient with bio balls. I also know that this might cause some clogging due to the smaller size of the media. My thought was whether holding some de-nitrate in a filter bag might help keep it from clogging.

Other ideas were of ceramic rings, bio stars etc. Is there any reason to go for one over the other, or mix them in layers?

On another thread, one person had made two PVC pipes, with one full of the coils and the other full of the media, this seemed to be one way of keeping the height down if that was important. Just another idea I thought that should be noted on this great thread.

Also, I hear of dosing carbon in the form of vodka or sugar. Could someone with experience discuss this and how it is best done.

Again Thanks to everyone that contributed to this thread, it has fundamentally changed my design I will be underytaking.

My goal is to build a 2-3 coil denitrator. According the the research above, increasing the coils that send water down to the media (which is then shared for all the coils output) creates the most efficient way of expanding the system. The limit is the coils, not the media.

3 coils might be overkill, but in my mathematical calculations, I should be able to fit 3 in the 1" space that using a 3" tube to wrap around would allow for in order to fit inside a 4" PVC. 1/4" OD tubing would add up to 3/4" wrapped around each other. 50 feet of tubing is said to be enough for 1/4 OD but I suspect I will make it 60 to make sure since you want very little oxygen to enter the media. This works out that I would need the pipe to be about 20" long for the inner coil (outer coils will need slightly less).

I found some 1/4" OD black tubing that I will run down the outside of the pipe, with each coil glued to the outside of the last so all 2-3 coils will be ran down the outside being fed into the pipe roughly an inch from the bottom. I am planning to include either layers of media, or bags of different media including Kent's Nitrate Sponge and Seachem's De-Nitrate along with ceramic rings and possibly bio balls. I will design this with clogging in mind. With long enough inputs that I can attach simple needle valves to them to adjust flow between each. There will be a needle valve at the end to control output.

Input will be coming from either a corner filter moded to act in reverse (to create a prefilter) or from another pre-filter setup. The pump will be an aqualifter and the output will be sent into the back of the internal filter to mix with oxygenated water.

This is the plan. I'm now taking bets on how far off I will end up from this plan...

[hardiel]

But I had to tweak it a little.

Finally after a few months running it works. I did my CD in March following the instructions. Basically a 2 feet long 3'' PVC pipe and 70 ft of 1/4 tube and the rest bioballs.

First it was OK but then I had to include in the setup a small pump (aqualifter) because the tube clogged often and was really hard to put it @ 1 drop per second. The input is in the display tank and the output is in the sump.

The little thing I did is to put a feeder near the bottom. I took the idea from some fellow that sells Denitrators online and in his specs, he feed his either with vodka or sugar/water.

So I did it and it is working so far. Let's see the next problem (probably Nitrogen gas buildup inside).

Here are the pics. I painted in black because...I had this color. Probably light blue or green would look nicer.

If you have questions, please throw them. I'm no expert but I think I've been in all the stages of this project: illusion, desperation, despair, happiness, etc.




NITRATES ARE GONE!!!

[quahreef]

I was thinking of setting one of these up. Do people still run these or have they been shown to have issues?

[stephenhall1987]

Originally Posted by quahreef

I was thinking of setting one of these up. Do people still run these or have they been shown to have issues?

If done correctly they will help lower nitrates. If done incorrectly they have the potential of harming your tank with hydrogen sulfide.

The problem with them is that they only remove nitrates. They do not remove phosphates, silicates, etc.

[jon+megan]

Mine looks the same externally,inside is 100 ft of dripline tubing and about 20 nylon pot scrubbers.

mine outputs 2 pints per hour at 0ppm.