Project: ZERO Nitrate

[JardiniBoy]

Hey,
Just a clarification about denitrification. As a student microbiologist, anaerobic bacteria that use Nitrate (as an electron acceptor) don't use the oxygen component of NO3. Otherwise they'd be "aerobic". Anaerobic implies use of something other than O2, such as Nitrogen or Sulfur They use the Nitrogen.
They convert it in the following manner.

Nitrate --> Nitrite --> Ammonia --> N2 (Nitrogen gas)
Hence the name "Denitrification". It's basically the opposite of what the aerobic nitrification bacteria do.

So it seems plausible to me that you can have an increase in your nitrite/ammonia readings before they turn into N2 gas and escape into the atmosphere. Assuming you have the right bacteria in there. Many bacteria can only use (reduce) Nitrate to Nitrite and it ends there.

Sorry, I don't know much about denitrification with aquariums though. I've only observed potentially pathogenic types, though the denitrification process would be the same.

Zinq

PS. Not trying to make you feel stupid or anything of the sort. Just some commentary and speculation on my part.

I'm only still a newbie with this stuff ... but from what I read in another thread, the anaerobic bacteria needs oxygen just like any other organism. It is able to live in anaerobic conditions because it uses the oxygen from the nitrate. Thus the nitrate is not a food source, rather an oxygen source. Apparently they also need a food source and some fishkeepers have had success dosing sugar or vodka as a food source for for the denitrifying bacteria.

As I said, I'm not sure on the above so please feel free to correct me. (and I really mean please do ... any biologists out there?)

 

[JardiniBoy]

Hi JardiniBoy,

That is a serious undertaking

Have you checked out THIS thread? With some serious excess of Biohome Media you may be able to ditch those denitrators.

Just a reminder: Zero nitrates is good for /\/\onsters, but not good for plants.

HarleyK

Hey Harley

Yes I have seen it. I'm interested in getting some, but it isn't available in Taiwan. My setup is perfect for it's use because I could put it in the last compartment of my sump with a sh*t load of bio media before it to make nitrates and suck up the oxygen ... maybe I'll get some in the future. If I did, I would still continue to use my denitrators. They are very simple and need no maintenance ... "plug and play". They are also cheap and easy to make, so no worries about them.

Thanks for the advice!

 

[JardiniBoy]

So your saying we'll dump more ammonia back in the tank after the denitrator than what went into the denitrator?


JardiniBoy, the main reason the F/S crowd has little on denitrating vs S/W...S/W costs a bundle to do W/C's so they have incentive.

Dr Joe

.

I'm actually still not sure about all the chemistry involved here joe, but I know it's actually quite complicated. There are also bacteria that can live in both environments, and ones that convert the nitrate to a range of different substances.

As I said in the original post, I'm not trying to get out of doing water changes. My goal is to control nitrates by other means and do small weekly water changes to dilute DOCs and anything else my filtration doesn't take care of.

This will make my system more stable. When keeping red arowana, stability is important for good coloration. Apparently large water changes will negatively affect the color, and many of the pros (with beautiful, healthy reds) will opt for high nitrates and a stable system.

 

[JardiniBoy]

Good luck JardiniBoy, but honestly Purigen + a drip system would work much better IMO. Keep us posted.

Thanks bro!

I know about the benefits of purigen and I did consider a drip system when I originally had my tank made. The drip system wasn't an option for various reasons, and purigen isn't available in Taiwan, and when it does become it will be very expensive.

Thanks for the hints though..

 

[Zinq]

Well your statement is true in part. Anaerobic bacteria by definition don't use the Oxygen though. The ones we are talking about use the N part of it, the nitrogen. But it's not a food source for them. It has a similar function to what ppl need O2 for, we breath it. They "breath" in N. So basically not all organisms(refering mainly to bacteria) need oxygen in any form. But some will switch back and forth if given the option.

- Crash course in the science behind it-
I'm not sure what your science background so i'll keep this basic. Basically when we breath we need Oxygen to accept electrons. When we dont have oxygen, we die. Because our cells can't generate energy (It doesn't use the O2 as energy but it needs it to generate it, much like a fire needs O2 to burn but is not the source of fuel). Similarly SOME anaerobic organisms use the N part of Nitrate/Nitrite/NH3 as a source of "air" and they accept the electrons. Thus making energy. But obviously they (like us) can't survive off the N part of Nitrate alone, so they need amino acids, glucose, etc. Notice how it's not ALL anaerobic bacteria who use Nitrogen or Oxygen, some use sulfur and the end product is Hydrogen sulfide...Which kills you. (I think that's why ppl say aerate/stir your sand otherwise you get trapped gas)

 

[JardiniBoy]

nitrate should be the one of the worries, you also have other dissolved organic compounds, and a bacteria count in the water column. Not no mention the acids produced by nitrification.

I generally try to be positive in my replies ... but here I'm going to defer.

Please don't think I'm trying to get away from my water changes. I've come to accept that changing water is part of this hobby, and have come to enjoy doing mine. My hope is that, when i start running all my systems together (and start testing), I'll have low nitrates and will be able to do small weekly water changes which will stress the fish less..

You always chirp into these discussions with the same stuff about DOCs etc.. The above quote shows that I've already considered that point. If you don't have anything real to add or are just going to negative, rather don't post. If there are 10 positive posts and one bs negative one ... you always know who it's gonna be from.

Rant over... *phew*

 

[JardiniBoy]

Iv'e been running the Korallin S4002 Sulfur Denitrator for 3 month know and it's works very well. I recently added a 50' coil in front of it to help ensure low O2 water gets to it. It's input water depending on the time of last WC is 20-50 mg/L and output is 0-5 mg/L with a rate of approx 35 gal/Day. I had tried DIY Coil unit before and they worked well, but they would plug off after a few months, but I have been thinking of building another one using some different ideas. As for DSB's I have never had one, although lately I have been thinking of building one, anything to help control nitrates. How did you build your DSB?

A RDSB is basically a sand bed of over 8" with a strong prefiltered water flow over it. The strong flow prevents detritus from settling into the bed. The nitrates will diffuse down in to the anaerobic regions within the bed and be consumed by the denitrifying bacteria.

Many SW bros who had been battling nitrates without any success for ages installed one of these and it sorted out their problems in a month!

Check out the link in the original post for more info on this..

 

[JardiniBoy]

Well your statement is true in part. Anaerobic bacteria by definition don't use the Oxygen though. The ones we are talking about use the N part of it, the nitrogen. But it's not a food source for them. It has a similar function to what ppl need O2 for, we breath it. They "breath" in N. So basically not all organisms(refering mainly to bacteria) need oxygen in any form. But some will switch back and forth if given the option.

- Crash course in the science behind it-
I'm not sure what your science background so i'll keep this basic. Basically when we breath we need Oxygen to accept electrons. When we dont have oxygen, we die. Because our cells can't generate energy (It doesn't use the O2 as energy but it needs it to generate it, much like a fire needs O2 to burn but is not the source of fuel). Similarly SOME anaerobic organisms use the N part of Nitrate/Nitrite/NH3 as a source of "air" and they accept the electrons. Thus making energy. But obviously they (like us) can't survive off the N part of Nitrate alone, so they need amino acids, glucose, etc. Notice how it's not ALL anaerobic bacteria who use Nitrogen or Oxygen, some use sulfur and the end product is Hydrogen sulfide...Which kills you. (I think that's why ppl say aerate/stir your sand otherwise you get trapped gas)

Thanks for the details bro! It's still a little hazy, but getting clearer.

With the above in mind, what would be your thoughts on dosing a food source for the bacteria (sugar/vodka) and how would I go about doing it?

Also I have seen some RDSBs with sulphur (in a solid form) at the bottom below the sand. Would this increase the efficiency of the RDSB? I know there are some commercial sulphur denitrators and bro Boydo is using one with some success.

Thanks again!

 

[Zinq]

I've never heard of an RDSB. It seems pretty interesting though. I can see how it can make an anaerobic environment (at least in the deeper regions of sand) for ur bacteria and denitrifying some nitrates. But when installing it, do you have to add some specific sort of bacteria or is it similar to the concept of cycling a tank where the nitrification bacteria are already in the environment?
I'm guessing nothing is added...Anyways...My only quirk with the sand bed system is how does the N2 escape the sand? Doesn't it just get trapped under the sand? I'm guessing a good way to see if ur bed is working is to poke it with something and see if bubbles come out. But for every single organism... ur poop is toxic to you, so excess of nitrogen would probably be detrimental to the organisms... A poke or two now and then would probably be good.

As for dosing food sources, I would probably go with sugar above anything else. Vodka is not generally good for your fish or bacteria. The alcohol will basically kill them all. It's like those alcohol sterilizing wipes. It'll kill ur bacteria. Dosage... I have no clue. Would have to do some testing for any sort of clue. I've never actually tried any sort of system that resembles an RDSB so no clue.

As for the sulfur thing. I also have no clue. I googled it and came across some chemical equations that appear plausible. Also read some explanations that also seem descent. But, it will increase your pH, so watch out for that. At the moment, I don't really know. I'm going to ask my friend, who is a ....i forgot what sort of engineer... It has to do with designing filtration systems for various things. He told me about his adventures working on a filtration system for a bunch of water loving zoo animals. So i'll get back to you on that.

 

[JardiniBoy]

I've never heard of an RDSB. It seems pretty interesting though. I can see how it can make an anaerobic environment (at least in the deeper regions of sand) for ur bacteria and denitrifying some nitrates. But when installing it, do you have to add some specific sort of bacteria or is it similar to the concept of cycling a tank where the nitrification bacteria are already in the environment?
I'm guessing nothing is added...Anyways...My only quirk with the sand bed system is how does the N2 escape the sand? Doesn't it just get trapped under the sand? I'm guessing a good way to see if ur bed is working is to poke it with something and see if bubbles come out. But for every single organism... ur poop is toxic to you, so excess of nitrogen would probably be detrimental to the organisms... A poke or two now and then would probably be good.

As for dosing food sources, I would probably go with sugar above anything else. Vodka is not generally good for your fish or bacteria. The alcohol will basically kill them all. It's like those alcohol sterilizing wipes. It'll kill ur bacteria. Dosage... I have no clue. Would have to do some testing for any sort of clue. I've never actually tried any sort of system that resembles an RDSB so no clue.

As for the sulfur thing. I also have no clue. I googled it and came across some chemical equations that appear plausible. Also read some explanations that also seem descent. But, it will increase your pH, so watch out for that. At the moment, I don't really know. I'm going to ask my friend, who is a ....i forgot what sort of engineer... It has to do with designing filtration systems for various things. He told me about his adventures working on a filtration system for a bunch of water loving zoo animals. So i'll get back to you on that.

From what I've read (and please bear with me here because I'm still a noob with this stuff) stirring the sand is a bad idea because it disturbs the different layers in the sand.

The layers are actually quite complex. There is the aerobic layer, the low oxygen layer and the anaerobic layer, with different bacteria living in each layer (many different kinds in each layer I think).

I guess if the nitrogen gas were to escape, it would be by the same way the nitrates got in ... diffusion. Higher concentration in the lower regions of the sandbed, lower above.

From the original link I posted, the guy who recommended the use of RDSBs has had them installed for many years and hasn't had a problem with "nasties" getting trapped inside. There are other people who have had different experiences though.

I think the keys are:
(1) remote from the rest of the system
(2) relatively high flow (compared to a coil denitrator)
(3) prefiltered water
(4) a dark environment is recommended
(5) nothing else in the RDSB except sand and water

The cool thing is that they are cheap to make, easy to install and maintenance free ... so worth a try IMHO. I must just get a decent test kit now and try to get some results.