DIY Ammonia dosing for low nitrate systems

[Randy Holmes-Farley Verified Community Expert]

Really? wow.
I'm going to have to re-evaluate my estimate of the likelihood of "someone in your house peed in the tank" as a mechanism for inexplicable ammonia spikes. (I do believe that has happened a non-zero number of times on this forum.)

lol

Normal ammonia in urine is about 0.1 to 0.8 ppm (10 to 80 ug/dL). See below

https://www.urmc.rochester.edu/ency...entID=ammonia#:~:text=Adults: 10 to 80 mcg/dL

• Adults: 10 to 80 mcg/dL

 

[taricha]

lol

Normal ammonia in urine is about 0.1 to 0.8 ppm (10 to 80 ug/dL). See below

https://www.urmc.rochester.edu/ency...entID=ammonia#:~:text=Adults: 10 to 80 mcg/dL

• Adults: 10 to 80 mcg/dL

So peeing in the tank adds an undetectable amount of ammonia (until the urea breaks down). Ya learn something new every day.

 

[collins.jason.k]

What an interesting concept. Thanks @Randy Holmes-Farley for sharing.

That's why I love this forum. So much information to digest and so many people getting involved. You guys rock!

 

[GARRIGA]

I was starting to think I could just pee in the tank and avoid the chemistry. Bummer

 

[shwareefer]

I've been dosing 6% Ammonium hydroxide for more than year each morning (1 drop per 10 gallons). It simply made sense to me to feed the nitrogen cycle and create the nitrate naturally rather than just dosing the end product. The fact that corals and algae can also utilize it and it's immensely cheaper than dosing nitrate are bonuses. My nitrate level fluctuated a lot with nitrate dosing but is stable at 10ppm with ammonia dosing. Not sure why that is, but I'm happy about it.

 

[Hans-Werner]

Another thing: urea is also slightly a carbon source. Still mostly a nitrogen source, but definitely also a carbon source.

I don't want to offend you, just out of curiosity. How does that work?

After hydrolyzis of urea by urease only CO2 and NH3 are left:

(NH2)2CO + H2O (urease)→ CO2 + 2NH3

 

[biom]

I don't want to offend you, just out of curiosity. How does that work?

After hydrolyzis of urea by urease only CO2 and NH3 are left:

(NH2)2CO + H2O (urease)→ CO2 + 2NH3

"The detectable in situ incorporation of 14C-labeled urea shows that the carbon of urea was assimilated by (marine) polar prokaryotes"

https://www.pnas.org/doi/10.1073/pnas.1201914109

 

[Hans-Werner]

"The detectable in situ incorporation of 14C-labeled urea shows that the carbon of urea was assimilated by (marine) polar prokaryotes"

https://www.pnas.org/doi/10.1073/pnas.1201914109

Yes, no doubt, urea is a carbon source, also the chemical equation shows, but I understood it, like it was an organic carbon source, which I still think it is not. These Thaumarchaeota also take up bicarbonate. So it's no surprise they also take up the inorganic carbon resulting from the hydrolysis of urea.

Nevertheless a very interesting article!

 

[biom]

Yes, no doubt, urea is a carbon source, also the chemical equation shows, but I understood it, like it was an organic carbon source, which I still think it is not. These Thaumarchaeota also take up bicarbonate. So it's no surprise they also take up the inorganic carbon resulting from the hydrolysis of urea.

Nevertheless a very interesting article!

That is rather philosophical discussion. Urea is organic compound and all the process from uptake of urea to incorporating its carbon into archaea's tissue happens inside the cell and even if there is stage in the process when carbon is in "inorganic" form before is assimilated does not mean urea is inorganic source.
Just thinking I dont think there is big difference how we will call it, it wont change the fact carbon from urea is incorporated into the tissue and not just lost as side product (as CO2).

 

[taricha]

Let me ask the urea "carbon source or not" question in an un-philosophical way.
Is breaking down urea for carbon an energetically favorable process (like other organic carbon sources)?
If so, then I bet urea would trigger a cloudy water bacterial bloom.
If grabbing the carbon from urea doesn't give energy then I suspect it wouldn't trigger a cloudy water bloom, but just be degraded in the background over time.

 

[brandon429]

I would really benefit from knowing an educated guess on how much 1 common goby degrades into liquid ammonia at the strength stated in this thread

for example, is one small citron goby equivalent to 3 drops of this ammonia here approximately? there are formulae to detect % ammonia yielded by x weight of protein and it would be neat to tie into panic threads where a goby dies in the tank and everyone wants to know if the tank will now die

what if the degree of liquid ammonia added here is equal to, or twice over a common small goby plus its added daily? that could give peace of mind to panicky cycle worry threads.


how many drops of ammonia is equal to a common clownfish?

one small goby = ~3 drops?

1 common ocellaris= 9 drops etc

 

[Dburr1014]

I was starting to think I could just pee in the tank and avoid the chemistry. Bummer

That's called carbon dosing... Apparently. LOL

 

[LadAShark]

I don't want to offend you, just out of curiosity. How does that work?

After hydrolyzis of urea by urease only CO2 and NH3 are left:

(NH2)2CO + H2O (urease)→ CO2 + 2NH3

No offense taken, here are some example sources:
https://pubmed.ncbi.nlm.nih.gov/31164875/https://www.researchgate.net/profil...OR-GREEN-ALGAE-SCENEDESMUS-SP-CULTIVATION.pdfhttps://www.sciencedirect.com/science/article/abs/pii/S0168165623000603
More commonly, some organisms can use carbon in urea outright for amino acid synthesis, less commonly, it can be used in other processes needing carbon. Urease is not the only enzyme that handles urea.

Let me ask the urea "carbon source or not" question in an un-philosophical way.
Is breaking down urea for carbon an energetically favorable process (like other organic carbon sources)?
If so, then I bet urea would trigger a cloudy water bacterial bloom.
If grabbing the carbon from urea doesn't give energy then I suspect it wouldn't trigger a cloudy water bloom, but just be degraded in the background over time.

Multiple studies suggest that the presence of urea does indeed help blooms to occur, more so than other nitrogen sources.

That's called carbon dosing... Apparently. LOL

It would be both nitrogen and carbon dosing. Sure, urea itself is somewhat of a carbon source (though mainly a nitrogen source), but something that wasn't mentioned is that some DOC's do make it out via urine, so it it is all the more carbon dosing lol!

 

[biom]

Let me ask the urea "carbon source or not" question in an un-philosophical way.
Is breaking down urea for carbon an energetically favorable process (like other organic carbon sources)?
If so, then I bet urea would trigger a cloudy water bacterial bloom.
If grabbing the carbon from urea doesn't give energy then I suspect it wouldn't trigger a cloudy water bloom, but just be degraded in the background over time.

Yes it will make water cloudy, I know this from experience (didnt pee, I had technical issues and dosing was easier) :beaming-face-with-smiling-eyes: But cloudiness of water could be because of nitrogen availability, not because of carbon.
I don't think breaking down urea for carbon is an energetically favorable process, it is probably neutral - enzyme catalyzed hydrolysis? But why it should be energy net positive to be considered organic carbon dosing? if it is neutral and carbon is used as "building blocks" in the amino acids for example? Just thinking loudly.

 

[biom]

https://www.researchgate.net/profil...OR-GREEN-ALGAE-SCENEDESMUS-SP-CULTIVATION.pdf

;) yeeeeees Bulgarian scientists

 

[taricha]

But why it should be energy net positive to be considered organic carbon dosing?

eh...i just made up in my head that a carbon source may need to be energy net positive to cause a robust bacterial bloom.
And when we say "carbon dose" in the hobby, we generally mean an organic carbon source that will stimulate growth of heterotroph bacterial biomass. That's kind of an implied meaning in our context.

 

[Randy Holmes-Farley Verified Community Expert]

eh...i just made up in my head that a carbon source may need to be energy net positive to cause a robust bacterial bloom.
And when we say "carbon dose" in the hobby, we generally mean an organic carbon source that will stimulate growth of heterotroph bacterial biomass. That's kind of an implied meaning in our context.

I agree. That’s how I would define organic carbon dosing: adding an organic material that provides energy when it is metabolized. I’ve not calculated the energetics, but it may be low and not that useful for this purpose.

 

[Enderg60]

Now if someone opens this thread on page 4 it will be all about peeing in your tank.

My job here is done!

 

[GARRIGA]

Now if someone opens this thread on page 4 it will be all about peeing in your tank.

My job here is done!

I was really hoping it would be that simple. I can dose just about every hour. Benefit of getting old :face-with-rolling-eyes:

 

[LadAShark]

I agree. That’s how I would define organic carbon dosing: adding an organic material that provides energy when it is metabolized. I’ve not calculated the energetics, but it may be low and not that useful for this purpose.

Yes, aside from other dissolved organic carbons in urine, urea shouldn't be considered a great or even really a good carbon source. All it is is that the carbon in it can be utilized, especially if it's together with the nitrogen group. Just worth remembering that urea will cause more of a bloom than would be expected compared to ammonia for that reason.

I was really hoping it would be that simple. I can dose just about every hour. Benefit of getting old :face-with-rolling-eyes:

I wish, too bad even under ideal conditions our metabolic rates are very high relative to our systems, meaning our turnover is insane. You'd very likely get a bloom if your system isn't massive (of course this varies with a lot of factors, lol)

https://pubmed.ncbi.nlm.nih.gov/29540461/ wow would you look at that, tridacnids can use it as a nitrogen source as well as an inorganic carbon source. Who knows, maybe urine for a surprise if you have tridacnids. ;)