Denitrification

[largeload]

2 questions for the well informed 1) Why no discussion of denitrification units ? 2)what is better for an all fish system than if you are already using ls, lr, wet dry and protein skimmer? I,m considering setting up my 125 and I HATE WATER CHANGES. Your undivided attention would be greatly appreciated

 

[bang guy]

I think the theory behind the long-tube denitrifiers is solid. I've yet to hear from an experienced successful hobbiest that they had a good expierence.

 

[fda483]

I am like you - hate water changes. So I did some reading on denitrification units. Purchased one that held the water for a while and batched it back into the sump. It was controlled via an ORP monitor.
Results
!) Followed the directions line by line. Took about 3 months to slowly drop the ORP inside the unit to get the bioload anaerobic.
2) After that it maintained the tank at about 25ppm NO3 for about 6 months without doing any water changes. Never could get it below 25ppm NO3. Before the unit tank was between 25 - 40 ppm with monthly water changes.
The biggest problem with the unit was that ever few hours when it cycled the water back into my sump IT STUNK like you would not believe. If anyone worked in a micro lab when they clean out their incubators they will know that anaerobic smell. Not a pleasant thing to have in the house. Spoke to the manufacture they told me to raise the ORP level so it cycles more often. As expected it smelled a little less but the NO3 levels when up!!!
Bottom line for me, a lot of time, a lot of $$, a lot of stink for no real benefit. I am back to doing water changes.

 

[largeload]

We had a local fs dealt only in reef systems and his system used a sucrose based additive. His no3 was almost 0 now granted you don't have the buildup inreefs of waste but the site I've found to diy one also has a separate tank to reduce the smell. How big was the unit you used and what size tank and filtering did you have? ty

 

[beaslbob]

I want to thank the responses to this thread as I was wondering how denitrifying units worked also. As I suspected it is an anaerobic system and stinks.
Large: the best way of handleing nitrAtes is with plant life. That way you rely on aerobic bacteria to produce the nitrogen products which the plants eat. Additionally, by absorbing carbon dioxide ph is buffered. And in this process the plant life filters out heavy ions, buffers trace elements, and provides hiding places and food for the livestock.
that sure sounds a whole lot better than the equipment described here.

 

[bang guy]

Hi Bob
What Trace elements do Marine Algae buffer and what does that mean?
I also use Algae to remove the Nitrate & Phosphate that the DSB misses.

 

[reefnut]

largeload, I have found that by doing small water changes more often (5g a week for me) that the process becomes pretty easy. Like you I hated when it came time for a water change because of the hastle... now it's quick & simple. Just a thought.
BTW, I also use macro algae in a fuge for nitrate and phosphate export but water changes are a good practice even if you do not have a nitrate problem.

 

[beaslbob]

Originally posted by Bang Guy
Hi Bob
What Trace elements do Marine Algae buffer and what does that mean?

Hi bang and how's nemo.
Just something i read someplace. Obviously the plant life filters out ions therefore reduce any build up of trace elements. the the livestock eat the plants providing trace elements to the livestock.

 

[reefnut]

Bob, I'm not trying to be antagonistic but do you understand what "Trace Elements" are?

 

[beaslbob]

Originally posted by ReefNut
Bob, I'm not trying to be antagonistic but do you understand what "Trace Elements" are?
If I don't you are probably going to tell me.

Stuff like calcium, mag, strontium, iron, potassium, copper, and a whole bunch of other stuff i can't pronounce (or spell)? Available in trace quantities and needed by our livestock?
that close enough even though I didn't mention all of them?

 

[reefnut]

Originally posted by beaslbob
If I don't you are probably going to tell me.

Nope, you bore me :sleepy:. I was just wondering.

 

[largeload]

How many of you responders are all fish? If I can maintain 20 parts or less, established fish can do well. It's the new additions that become stressed get diseased and cause all of the problems. I'm not familiar with the plant algae systems but they require additional care also. I assume this process is outside of the primary tank, is that the refugium I read here? If I start up my tank I really want to give denitrification a whack.

 

[beaslbob]

Originally posted by largeload
How many of you responders are all fish?
I got some corals LOL
If I can maintain 20 parts or less, established fish can do well. It's the new additions that become stressed get diseased and cause all of the problems.
Fish can tolerate nitrate levels much higher then 20ppm. Even with normal slow accilmation
I'm not familiar with the plant algae systems but they require additional care also.
if you do nothing plant life will grow on its own. Adding plant life to limit the ugly algaes is the absolutly easiest aspect of aquarium keeping. Much easier than keeping the fish or corals for instance.
I assume this process is outside of the primary tank, is that the refugium I read here?
Well that is an external refugiun. No plants can grow in tank and a refugium can be in tank also.
If I start up my tank I really want to give denitrification a whack.
Then the easiest to maintain, simplest, most reliable and most effective is to use plant life. reducing nitrogen compounds is only one of the positive values of plant life. Basically, with plant life you get a balanced complete ecosystem. If you want another whiz bang super duper gadget then do it. You should also expect constant worries, tweeking, failures and so on.
for instance I'll just bet that no one has told you that one of the products af anaerobic nitrate reduction is ammonia. Yep the same ammonia that resulted in nitrates to begin with. One by product of plants by contrast is food.

 

[reefnut]

Originally posted by largeload
If I start up my tank I really want to give denitrification a whack.
I would be interested in your results!! Mine is a reef tank. I had a FO tank for a while... I think the same principles apply, just with a FO you don't have to worry about the water chemistry quite as much. I would still aim to keep your nitrates and phosphates as low as possible to minimize excess algae growth.
A GOOD skimmer would be a good investment if you do not have one. IMO a good skimmer will do more than the average fuge. Both working together tends to work well.
Good Luck,

 

[bang guy]

Originally posted by beaslbob
for instance I'll just bet that no one has told you that one of the products af anaerobic nitrate reduction is ammonia. Yep the same ammonia that resulted in nitrates to begin with. One by product of plants by contrast is food.
Really? I'm not aware of this.

 

[bang guy]

Ahhh... are you refering to anaerobic Sulfate degredation? This
"Ammonium (NH4+) is released from organic matter during degradation by sulfate reduction. Ammonium is a bioavailable and is readily taken up by plants."
Garnered from Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic; suboxic diagenesis, Oxford. 43, 1075-1090.
Anaerobic degredation should only occur in sandbeds without a large diversity of sand bed infauna or deep under the rock base. This shouldn't occur that muck in a healthy sand bed.

 

[cincyreefer]

Bang Guy- I could be wrong, but I think you have it backwards. As I understood it, the by product of anoxic respiration was nitrogen, and the by product of anaerobic respiration was Ammonium. I thought that anoxic respiration was what we want, but is near impossible to achieve since it is so difficult to get enough oxyen down deep into the sandbed.

 

[beaslbob]

well actually I was refering to the chart of the nitrogen cycle that comes with the mag pumps. And your are correct nitrogen gas is the final end product.
Although there may be various ways of reducing the anaerobic ammonia, the chart does shows ammonia being generated by the DSB. And if the ammonia is so readily taken up by plant life, then why not recognize and emphasize the plant life to begin with? After all plants life converts both the ammonia and nitrates to fish food, shelter, corraline algae and the like.
But then if you want to say the DSB did all the work i guess that is up to you.

 

[reefnut]

 

[cincyreefer]

I agree with you Bob (I can't believe I am saying that...), except that Ammonia (NH3) is not the by product of anaerobic respiration, it is Ammonium (NH4). But Ammonium does contribute to unwanted alga. This is the reason why Plenum sandbeds CAN work better than DSB if they are setup and maintained correctly. With the larger size substrate, it allows for more oxygen to get into the sandbed which promotes anoxic respiration instead of anaerobic. However, IMO setting up and maintaining a good plenum is too much work and difficult. That is why i prefer nutrient export through macros (something I hear you talk about alot at times... ).