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Denitrate Tower - "Safe Denitrification"

26K views 42 replies 17 participants last post by  Mxx 
#1 ·
I’ve had a few questions about my Denitrate Tower, so I thought I would provide a thread with a few details.

The “Denitrate Towerâ€
 
#27 ·
BenHugs just directed me to this thread since I'm looking at ways to decrease my Nitrates.

I'm definately will be trying to build a Coil Denitrator, but I had the idea today as to whether anyone has ever tried to use an air pump to create the flow for the denitrator.

In my mind, if I attach a vertical section on the output side of it, the venturi effect created by the air (much like a sponge filter) might move enough water through the denitrator to create 80 drops/minute as I have researched to be a good amount.

Perhaps this would make it harder to adjust, though I can't see why I couldn't add a ball valve before the air to adjust the speed.

Just curious as to your thoughts about it.
 
#28 ·
jfly said:
your daughter calls it "king kong's bong!?!?!?" hmm and how old is she.. i'd kill myself if my kid said that, then myself for my parenting faults
you would kill yourself, and then yourself?

i think you have more to worry about than your parenting skills

that aside, awesome project here, was a good read interesting stuff keep it up ;)
 
#29 ·
Sorry to dig up an old thread, but I wanted to update it with a final piece of data. The filter has yet to be broken down and cleaned, but it now needs it. It is no longer able to maintain zero nitrates. Nitrates are now increasing about 5ppm per week, which is still a significant reduction over what would occur if the filter were not in place.

So now I know.... I get about 6 months before it needs cleaned. Now it's time to replace it with King Kong's bong (filled with new media). The current filter will be broken down, the media cleaned, and in about 3 months, added back to the system, to run in conjunction with King Kong's Bong. So every 3 months, one of the two will be broken down and cleaned. In theory, I should be able to maintain zero nitrates almost indefinately. The next question to answer, is how long can I continue to recyle the media?
 
#31 ·
I guess not, since I'm not familiar with the name. Do you have a link?

EDIT......
Disregard.... googled it.

I am not familiar with the specific product, I am familiar with the technology (been waiting on products to start appearing on the market). If they are using PCLs (polycaprolactone) I wonder how they got around the Tetra Patent?

http://www.freepatentsonline.com/7244358.html

I'll research a bit more and post back.
 
#32 ·
There is a suprisingly lack of information on the product. I would like to know specifically what biodegradable polymer they are using. As previously mentioned, Tetra/Marineland/United Pet Group has the most effective of these materials (polycaprolactone) locked up in patent. Perhaps that is why there an absence of information.... don't want to be found in violation of a patent.

Another concern is that it is marketed specifically for salt water tanks as a alternative to Vodka dosing. My experience with Vodka dosing in freshwater is that it's not a good thing. You wind up with heavy bacterial slime on everything and substantially increase the colonies of heterotrophic bacteria in the tank, many species of which are pathogenic (causing everything from kidney infections, to bloat, to pop-eye, to flesh ulcerations). They also specifically mention having the outflow from the NP-BioPellet reactor releasing into the intake of a protein skimmer to minimize the amount of bacteria being released into the tank. The "released bacteria" is also a food source for corals and other saltwater critters that do not exist in a freshwater tank. For me, another warning sign against use of this product in freshwater (or by anyone other than an advanced aquarist).

The Tetra patent (see previous post for a link to the patent) has resulted in the release of this product (Instant Ocean Natural Nitrate Reducer)
http://www.fosterandsmithaquatics.com/p ... atid=21331

Which I have been using for a few months as a test in my guppy tank and one of my Angelfish tanks. My issue is that I just don't allow myself not to perform water changes to determine how effective the product is. So I use the product and continue my water changes. But I have seen some results and my results don't match the patent. I'm getting better results in the sand tank than I am in the gravel tank. Another problem with it's use in a gravel tank is that if you gravel vac (which you should), you vac a good percentage of the product out of the tank. I don't mess with my sand, other than to vac up whatever is visible on the very top of it.

In the guppy tank (actually, it's a livebearer tank, containing guppies, platies, and swordtails -as well as cories) I am now going two weeks between water changes. Nitrates in this tank, before I did anything to control nitrates, (believe it or not) were the worst of any of my tanks. I added an Eheim 2213 filled with SeaChem Matrix and started using this product. Now... I don't quite hit 20ppm within two weeks. I was hitting well over 20ppm within a week (very heavily stocked). Supposedly, according to the product (with it's weekly use), nitrates should stablize between 10ppm and 20ppm, without water changes. I just can't allow myself NOT to perform a water change for a month to see what happens. I need to unpucker the sphincter muscles, on the subject.... I guess. :D

In the Angelfish tank (gravel), nitrates where not exceeding 10ppm in a week and still are not, but I continue with weekly large water changes on this tank. There certainly is not any evidence of a reduction of nitrate creep in this tank, at least not with the weekly large water changes in play.
 
#33 ·
As a followup... I sent an email to Instant Ocean asking them about "Natural Nitrate Reducer" use in Freshwater. Their response.... it does not work in Freshwater. So if Natural Nitrate Reducer is not going to work in Freshwater, then NP BioPellets most certainly are not.

Instant Ocean's recommendation? Being from the same parent company as Tetra, they recommended Tetra Easy Balance. Yeah.... right. That **** is not coming with a lightyear of one of my tanks.

Anybody wanna buy a couple of bottles of "Natural Nitrate Reducer"... cheap. :lol:
 
#35 ·
I have not given up yet..... because Tetra sells (what I assume is) an identical product to "Natural Nitrate Reducer" in Europe (Tetra Nitrate Minus... which has Angelfish on the bottle cover). Historically, Instant Ocean is the saltwater arm, "Tetra" is the freshwater arm, of the same company. I've reread the patent upteen times. There is no mention to saltwater (no mention to freshwater either). It does identify the positive effects on plant root structures, which I would take to indicate freshwater use.

Now... all of that said, I would assume NP-Biopellets are using polyhydroxybutyrates (PHB), not polycaprolactone (PCL), as PHB's are not covered by the Tetra patent. NP-BioPellets are also using a very much larger pellet (Natural Nitrate Reducer uses a powder suspended in a liquid).

If nothing else, NP-BioPellets could be used with the addition of a functional skimmer. In freshwater, this is difficult, unless you have $1,000 to cover a Clarity. I am not sure why NNR is "saltwater only" but intend to find out.
 
#36 ·
I actually have a functioning skimmer on my malawi tank. It works on gravity with airstones to suppliment it. I do run some marine salts (1 scoop per 5g) and have a ph of around 8ish. I also keep my temp a little lower at 77 as that helps with skimming. I would show you pics but I need to build a better version. I'm going to see if I can find the link of a similar design. My skimmer requires a sump to work.
 
#38 ·
I thought I would drop a quick update. I finally broke down the old filter and replaced it with the "Big Ugly Green Thing" (what my wife calls it), aka "King Kong's Bong" (my daughter's name for it).

This will be the third "recyling" of the media in this filter. I'm anxious to see if it continues to work after this latest cleaning.

Anyway, as my wife was complaining as I set it up, I claimed "Hey, at least I painted it green to match to house colors". :lol:

Here is a full on shot of the filter. It's in a small bucket just to ensure there is no leakage. Access to the media is a threaded drain plug on the bottom.


And here it is in it's normal position (to the right of the photo), partially obscured by the cabinet I store my extra media in.


The filter had pretty much ceased holding nitrates to zero, with the decline occurring after 6 months of use. We'll see if it gets things back into shape. I expect it to take a month to "recycle".

Cleaning involved emptying the media into a large container, flushing it clean with tap water, stirring the media by hand to force the individual media pebbles to rub against each other, then boiling for about 30 minutes.
 
#39 ·
That thing is ugly but it looks like a great addition to a fish room or in my case, I have a closet right next to my 75, I wonder if I could fashion something like that, shoved in the closet and invisible?

Also, I love the idea, not trying to skimp out on maintenance but just trying to provide the best environment for your fish. I talk alot about survival vs. thrival. If you got rid of half or more of your filtration, did a 20% water change twice a month (and occasional big water change when nitrates got super high) your fish would not die. However, they wouldn't have the quality of life nor display the coloration, personality or natural behavior that they most likely do in your tank. I just love that instead of using your denitrate tower as a way to not do any water changes, your doing it as a way to provide pristine water. Good for you! Heck and maybe your like me and you love to perform aquarium maintenance! I love it when I change the water, now, when family members want to use the bathroom and there is a silicone hose running into the bathroom sink THEY don't like it so much, but you know, I'm still having fun :lol:

-John
 
#40 ·
kmuda said:
The filter had pretty much ceased holding nitrates to zero, with the decline occurring after 6 months of use. We'll see if it gets things back into shape. I expect it to take a month to "recycle".
Hey Kmuda, I've come across your thread a couple of times, and I'm wondering if you could give us an update? I'm thinking about building a denitrator...
 
#41 ·
Hi Kmuda, great thread. And very helpful in terms of providing actual information based upon personal experience with denitrification. I joined this forum just to contribute to this discussion, so I hope that some people are still listening to this thread!

I'm trying to figure out the optimal approach for my own intended denitrification, so if you could further comment on a few things then that would be much appreciated.

I'm reading a lot of mixed opinions on Seachem denitrifying media, and I'm a bit surprised by certain aspects of how you've approached your denitrification filter. Let me explain, in reading Ecology of the Planted Tank by Walstad, she talks about how biofilms are actually a complex bacterial ecosystem composed of many layers of different bacterial species. (And biofilms are good of course, for they are the bio-filtration itself. In any case, in an established bio-film, the upper layers can actually consume all the oxygen, which supposedly enables the lowest layers to be composed of denitrifying anaerobic bacteria.

I'm not quite sure why your filter then ceases to function effectively after a few months, for denitrifying filters are just supposed to get more effective over time? Is it that it simply becomes physically clogged to where all flow through the filter is significantly reduced?

I was quite surprised that you actually remove the media and boil it, as anaerobic bacteria supposedly take weeks or even months to fully establish themselves. Have you ever tried simply cleaning the media manually by rinsing it under a strong jet of water instead, to get rid of any 'silt' on the surface? Perhaps if you ran the water through a prefilter stuffed with foam or floss which you instead rinsed regularly then you wouldn't in any case be getting any 'silt' into the filter?

I'm just surprised that your filter seems so finicky in terms of its effectiveness for denitrification. Have you considered using Seachem Matrix or Pond Matrix instead? As those have larger 'nugget' sizes, I thought they might be less sensitive to variations in flow then the smaller De*nitrate which you are using. And with only 30 gph going through a filter of this length, I even wonder if you're getting into the realms of a traditional anaerobic denitration coil filter, and whether all the oxygen is consumed before the water passes all the way through, which is perhaps something to do with why you're getting varied results?

Another factor is that denitrifying bacteria also require a compound which can act as an electron donor in order for it to chemically reduce nitrate molecules. And for that reason, aquarists add sugar, a few milliliters of vodka, or Tetra Nitrate Minus to their tanks. Municipal wastewater plants use a product called MicroCâ„¢ which is apparently similar. So perhaps when you're not getting denitrification, it has something to do with a lack of an available carbon source in the water.

Personally I'm considering minimizing water changes in my planted tank to enable DOC's (dissolved organic carbon), to build up a bit in my planted tank in case that helps achieve denitrification. I haven't yet found a conclusive answer through research as to whether this would though. I will also need to stop using activated carbon in my canister filter as well if that is the case. Anyone? Are DOC's a carbon source which would successfully fuel denitrification?

I suppose I'd personally plan to use Seachem Matrix or Pond Matrix, or possibly sintered glass in my filter, so that I wouldn't need to worry too much about maintaining flow rates as carefully as you're having to. And as the internal area is considerably greater, would they perhaps have greater denitrification capabilities than an equal volume of De*nitrate? Please advise if you can, thanks!
 
#42 ·
Mxx said:
Another factor is that denitrifying bacteria also require a compound which can act as an electron donor in order for it to chemically reduce nitrate molecules. And for that reason, aquarists add sugar, a few milliliters of vodka, or Tetra Nitrate Minus to their tanks. Municipal wastewater plants use a product called MicroCâ„¢ which is apparently similar. So perhaps when you're not getting denitrification, it has something to do with a lack of an available carbon source in the water.

Personally I'm considering minimizing water changes in my planted tank to enable DOC's (dissolved organic carbon), to build up a bit in my planted tank in case that helps achieve denitrification. I haven't yet found a conclusive answer through research as to whether this would though. I will also need to stop using activated carbon in my canister filter as well if that is the case. Anyone? Are DOC's a carbon source which would successfully fuel denitrification?
Are there any other ways to add DOC's to your sytem besides the 3 methods you mentioned above? Wouldn't having a planted tank supply enough DOC's to our system especially if you had a CO2 system so your plants could absorb the CO2 and not the organic carbon in the water?
 
#43 ·
Agridion said:
Mxx said:
Another factor is that denitrifying bacteria also require a compound which can act as an electron donor in order for it to chemically reduce nitrate molecules. And for that reason, aquarists add sugar, a few milliliters of vodka, or Tetra Nitrate Minus to their tanks. Municipal wastewater plants use a product called MicroCâ„¢ which is apparently similar. So perhaps when you're not getting denitrification, it has something to do with a lack of an available carbon source in the water.

Personally I'm considering minimizing water changes in my planted tank to enable DOC's (dissolved organic carbon), to build up a bit in my planted tank in case that helps achieve denitrification. I haven't yet found a conclusive answer through research as to whether this would though. I will also need to stop using activated carbon in my canister filter as well if that is the case. Anyone? Are DOC's a carbon source which would successfully fuel denitrification?
Are there any other ways to add DOC's to your sytem besides the 3 methods you mentioned above? Wouldn't having a planted tank supply enough DOC's to our system especially if you had a CO2 system so your plants could absorb the CO2 and not the organic carbon in the water?
I'm guessing there must be various other ways to add organic carbon, but I'm not sure in what forms works as is necessary. I guess that I end up with a few questions I'm wondering about here;
A: Does DOC act as a carbon source for denitrification?
B: What does this do to the DOC molecules then? Destroys them somehow?
C: To enable anaerobic denitrification, should I not use activated carbon in my filter as that removes the DOC's I may need for denitrification?
D: Does the use of a powerful UV sterilizer oxidize the DOC's and thus render them incapable of being used to enable denitrification?
E: What is the best size media to use in a canister filter to achieve the most effective denitrification, the smaller Seachem De*nitrate or the progressively larger Matrix or Pond Matrix?
 
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