DIY Coil Denitrator Questions

Toddo

Native Species Only
Feb 26, 2009
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I am thinking about building a coil denitrator for my 125 fresh tank to supplement nitrate removal, and I am looking for opinions. I have a requirement for very very low nitrates.

Will a coil denitrator be effective enough to warrant building? If so, what size would it have to be to be effective? From what I have read, it should be 4 inch pvc about 30 inches long.

In addition, I am running ion exchange resins in my canisters to remove nitrates (Along with weekly water changes of course).

Does anyone have experience with fresh water denitrators? I searched the forum but some of the posts I found were older (back to 2005).
 
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i run a fluidized sand filter on each of my tanks along with other filters all freshwater is that the same thing? i use the coralife sea storm they are long glass torpedo looking gizmo's lol

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Hmmm. I don't know what a Mangrove Sump is, but I'll find out. I have thought about an algae scrubber also. A bit more involved, but definitely effective.

Here is a link to a DIY Denitrator and the principle of it's operation.

http://saltaquarium.about.com/od/diydenitratorplans/ss/sbscoildenitrat.htm

Obviously this is for a salt tank. However, I have read where it can be effective on fresh water also.

The build is simple enough. I was just wondering if its worth it.
 
I did a denitrator build a little over a month ago, but have kept pretty quiet about it because it was such a failure. I changed the standard design a bit. I used about six feet of 4" PVC, capped it. Tubing runs through the cap and inside through to the other end of the tube, and water must travel through porous gravel media to get to the exit in the same cap. My solution to their "coil" was to leave the rest of the 100' of 1/2" vinyl tubing in the box it came in. The water circulates through it before it enters the PVC. A small circ pump and a ball valve regulate the flow.

I haven't "fed" the filter anything (sugar, sulfur, etc.). It's been about month at a couple drops per second, and filter has been completely ineffective.
 
Hmmm... interesting. Fresh water, right?

Is your 4 inch tube mounted vertically? And is you small tubing coiled vertically also and completely in the dark? From the diy plans I read those were all critical (but I really don't know for sure). I did see one that used black tubing and was coiled outside the big tube instead of inside it.

Also, I have read that you wont see results for 6 to 8 weeks. Drip rate should be 80 drips/sec until it is working, then 160 drips/sec after that.

Or so I have read.....

Thanks for your reply.
 
Drip rate correction.... that should be per minute and not per second
 
Hmmm... interesting. Fresh water, right?

Is your 4 inch tube mounted vertically? And is you small tubing coiled vertically also and completely in the dark? From the diy plans I read those were all critical (but I really don't know for sure). I did see one that used black tubing and was coiled outside the big tube instead of inside it.
Yes, Freshwater. Being used with a 75 Gallon tank. The PVC is standing upright, with the entry and exit cap at the top. The whole thing is in a dark service basement (where it can leak if it wants to), and the roll of "extra" tubing is in a cardboard box. I believe the box is sitting upright, so the roll is up on one edge rather than flat.

It is challenged by an excessive nitrate load from the tank, which is full of goldfish. Initial reading are often in excess of 60ppm. Even so, I'd expect some results as I made a larger-than-recommended filter tube. That design choice was also taking into account that a low drip rate would never have a chance to make a difference in the tank. This all reminds me that it has been a couple weeks since I tested its output, and I should probably take a fresh reading.
 
I kinda skimmed through the previous posts. thought I'd say that because I typically read every post in the thread before I'd comment.
With that said, here goes...

I used to read about these types of contraptions. But never liked all the possible screw ups that could happen. Kinda like these commercails on TV... This will fix this... BUT, could cause 20 other problems while doing it. Then they say, Ask your dr. about this stuff. Which then I'm hoping that if anyone actually did ask their dr. He would slap'em up side the head, and point at all the stuff they already warned them about in the commercial.

Ok lol, back to de-nitratin'....

I did try one thing a few years back, that was borrowed from them reef folks.
And that was a plenum. Seemed to have worked. Nitrate did go to zero in the tank. Its not really something I'd recommend. I was bored, and this was a cheap experiment.
I didn't get to any long term conclusions, sense it was taken down with in a few months. It could have been interesting sense I DIY the whole filter system. Baddest lil 25g filter I ever saw. And I made it. lol
Goes with the "want something done right... DIY" thing. ;)

NOW
I like plants!
What kept me from trying plants for sooo many years, was that. Everything I was reading, was talking about major lighting and co2 systems to have any luck. But I'm learning different now, that I've actually tried some.

Soooo.... If its possible to set-up something in the stand. I'd imagine something as small as a 10g would be plenty. You could easily keep the nitrates very low.

Just off the top of my head. I'd say something like a 10g with a 30ish watt cf over it. With some Hygrophila corymbosa in 2" of flourite. I've had good success growing this, and it would be very easy to maintain.
Then have Only around 10 gph moving to and from it. Via either the tank or better yet from a sump(if your using one).
The gph could be adjusted later, but I'd keep it real low to start with.
With this, you could even add a DIY CO2 to the 10g, and not worry much about co2 loss for the plants.

Just some off the wall/head thoughts about a simple, not so dangerous possible alternative.

I haven't done anything like this... Yet. But have done some thinking about it for the indoor pond. Mainly because of trying to light add co2, etc to that big of a foot print, would be uberly rediculasly expensive.

Why this Wouldn't work... IDK? :)
 
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