DIY Ammonia dosing for low nitrate systems

[biom]

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.

Agree on definition. But then maybe urea could be organic carbon dosing because metabolisation of whole molecule urea, not only its "carbon" part could be energetically net positive, at least for some algae as some of the abovementioned papers suggested.
Meaning also dosing urea could be bad for reef tanks because will stimulate more algae growth than growth of heterotroph bacteria.

 

[Hans-Werner]

When we say carbon dosing and talk about resulting cloudiness we usually mean organic carbon dosing and bacterial blooms of heterotrophic bacteria.

The hydrolysis of urea must be energetically favourable to my understanding since it takes place spontaneously although very slowly. Urease speeds up this process by 10^14 times.

Nevertheless the resulting carbon is CO2, inorganic carbon. The carbon seems only to be used by autotrophic organisms/for autotrophic carbon assimilation and not for energy in heterotrophs. It does not nourish heterotrophs and cannot cause blooms of heterotrophic bacteria. It also doesn't consume O2 and in sum is just a hydrolysis that results in inorganic molecules.

 

[Randy Holmes-Farley]

Agree on definition. But then maybe urea could be organic carbon dosing because metabolisation of whole molecule urea, not only its "carbon" part could be energetically net positive, at least for some algae as some of the abovementioned papers suggested.
Meaning also dosing urea could be bad for reef tanks because will stimulate more algae growth than growth of heterotroph bacteria.

Here's some data:

Table 2 Thermodynamic parameters for the formation of the urease–urea complex in the urease-catalyzed hydrolysis of urea, obtained from temperature-dependent measurements of K M

ΔH o (kJ/mol)	ΔS o (J/mol K)	ΔGo298Δ�298o (kJ/mol)
−12 ± 1	7 ± 3	−14 ± 2

Temperature- and pressure-dependent stopped-flow kinetic studies of jack bean urease. Implications for the catalytic mechanism - JBIC Journal of Biological Inorganic Chemistry

Abstract Urease, a Ni-containing metalloenzyme, features an activity that has profound medical and agricultural implications. The mechanism of this activity, however, has not been as yet thoroughly established. Accordingly, to improve its understanding, in this study we analyzed the steady-state...

link.springer.com

For comparison, glucose is far, far higher:

Metabolic Energy - The Cell - NCBI Bookshelf

The reaction yields a large amount of free energy: ΔG°′= -686 kcal/mol.

 

[WhatCouldGoWrong71]

@Randy Holmes-Farley I have my Ammonia Chloride stock solution made in a liter bottle. I am just unsure of the exact dose amount per 26g to use. Does each 2.3ml of stock solution to dose equal 0.1 PPM of ammonia? I appreciate you sharing this article with me regarding my thread of "two tanks and neither have any nitrate". I just want to make sure I dosing correctly. And, also what would be the "max" ML stock solution one could add in a 24 hour period per 26 gallon?

Dosing

Don't be overly afraid of dosing ammonia due to toxicity, but one cannot dose substantial amounts all at once. IMO, it is safe to add 0.1 ppm ammonia (equivalent to 0.36 ppm nitrate) at once to any reef tank, and one can likely add more, if it mixes in well. Don't dose it right onto a fish, but dosing 2-3x that amount at once is also likely OK. Of course, using a dosing pump to spread out the dosing is fine and may be preferable, but be sure to guard against dosing pumps out of control (e.g., stuck on). Stock solutions can be increased or decreased in potency to match pumping needs. The ammonia could also be put into an ato since exact daily dosing is not required.

To add 0.1 mg/L ammonia to an aquarium, you would need to add 2.3 mL of either stock solution to a 100 L (26 gallon) aquarium. You may need to add this amount multiply times per day to dose enough.

 

[Randy Holmes-Farley]

@Randy Holmes-Farley I have my Ammonia Chloride stock solution made in a liter bottle. I am just unsure of the exact dose amount per 26g to use. Does each 2.3ml of stock solution to dose equal 0.1 PPM of ammonia? I appreciate you sharing this article with me regarding my thread of "two tanks and neither have any nitrate". I just want to make sure I dosing correctly. And, also what would be the "max" ML stock solution one could add in a 24 hour period per 26 gallon?

Dosing

Don't be overly afraid of dosing ammonia due to toxicity, but one cannot dose substantial amounts all at once. IMO, it is safe to add 0.1 ppm ammonia (equivalent to 0.36 ppm nitrate) at once to any reef tank, and one can likely add more, if it mixes in well. Don't dose it right onto a fish, but dosing 2-3x that amount at once is also likely OK. Of course, using a dosing pump to spread out the dosing is fine and may be preferable, but be sure to guard against dosing pumps out of control (e.g., stuck on). Stock solutions can be increased or decreased in potency to match pumping needs. The ammonia could also be put into an ato since exact daily dosing is not required.

To add 0.1 mg/L ammonia to an aquarium, you would need to add 2.3 mL of either stock solution to a 100 L (26 gallon) aquarium. You may need to add this amount multiply times per day to dose enough.

How much to add depends on your goals, but the last sentence is my recommendation. Add 0.1 ppm once, see what happens. Add it more tiems per day if all looks good and more is desired. Add smaller amoutns if anything looks off within 30 minutes of dosing.

 

[TheSheff]

I've been dosing Ammonium Nitrate for a couple of years, however it's not really mainstream due to the fact it is inherently risky, especially for newbies

I'm happy to see it discussed, but I think it'll be a while before you start to see ready made solutions on the shelf of the LFS.

It's only risky if you overdose it, right? Could cause a buildup of ammonia that can't get used up or converted fast enough?

 

[Randy Holmes-Farley]

It's only risky if you overdose it, right? Could cause a buildup of ammonia that can't get used up or converted fast enough?

There’s not going to be any buildup in a cycled tank.

 

[TheSheff]

There’s not going to be any buildup in a cycled tank.

You might have mentioned this in previous posts in this thread, but, where should we dose the ammonia? In the sump or directly onto a powerhead?

How quick would you expect to see results of dosing ammonia, if any?

I just ordered the ammonium chloride you mentioned, and I am excited to try it out.

 

[jda]

Someplace high flow is fine. Keep it away from the fish until it disperses.

 

[Makara23]

I recently started dosing ammonium chloride at about 0.1ppm every other day. Maybe it has been too short to tell, but no noticeable difference compared to dosing calcium nitrate.

I'm having doubts that it's benefiting corals, because nitrification bacteria might be consuming the ammonium chloride rapidly, turning it into nitrate, much quicker than what corals can absorb. When I started cycling my system before any livestock were in, at the end of the cycle there was sufficient bacteria to convert 1ppm of newly added ammonium chloride to nitrate in less than 24h. So by dosing just a tenth of this, there's no chance it stays in the water column long enough for corals to use.

In a mature system, isn't this how ammonia spikes (from anything dying) are dealt with? So again, by intentionally dosing small amounts, bacteria would just instantly chew it up.

 

[Randy Holmes-Farley]

I recently started dosing ammonium chloride at about 0.1ppm every other day. Maybe it has been too short to tell, but no noticeable difference compared to dosing calcium nitrate.

I'm having doubts that it's benefiting corals, because nitrification bacteria might be consuming the ammonium chloride rapidly, turning it into nitrate, much quicker than what corals can absorb. When I started cycling my system before any livestock were in, at the end of the cycle there was sufficient bacteria to convert 1ppm of newly added ammonium chloride to nitrate in less than 24h. So by dosing just a tenth of this, there's no chance it stays in the water column long enough for corals to use.

In a mature system, isn't this how ammonia spikes (from anything dying) are dealt with? So again, by intentionally dosing small amounts, bacteria would just instantly chew it up.

Thanks for the update. I have no idea if it is better than dosing nitrate, but it’s a great experiment.

It is certainly possible that there is a lot of competition for the ammonia, same as if a fish were excreting it.

 

[jda]

Once the tank gets past the bacteria-only phase of the cycle, there are other things than bacteria that use ammonia like corals, nems, algae, dinos, diatoms, . The competition is likely very high.

If you do not see any changes, it was just as likely that dosing the calcium nitrate was not doing anything either. If you already had even a small surplus of nitrate, this could indicated that nitrogen was never limited in the first place for coral use.

 

[GARRIGA]

Don't the bacteria utilizing this direct infusion of ammonium not require phosphates and thereby this process might create an inbalance or the assumption being phosphates tend to be inexcess of what's required? Granted rocks for example absorb and release phospahates and another concern but would seem that adding just the one element might be of concern in some systems. Speaking outloud trying to grasp all these nuiances.

 

[jda]

The way that I understand it, you need phosphorous* for bacteria to grow in numbers (new organic tissue), not for existing bacteria to turn nh4 into no2.

Dead bacteria are usually a wash with replacements, like recycling, more or less. Die off releases building blocks and growing populations need an influx.

*edit: said phosphates originally, but meant phosphorous. There are many sources of phosphorous in the reef tank beyond phosphates.

 

[Randy Holmes-Farley]

Don't the bacteria utilizing this direct infusion of ammonium not require phosphates and thereby this process might create an inbalance or the assumption being phosphates tend to be inexcess of what's required? Granted rocks for example absorb and release phospahates and another concern but would seem that adding just the one element might be of concern in some systems. Speaking outloud trying to grasp all these nuiances.

Th

The way that I understand it, you need phosphates for bacteria to grow in numbers (new organic tissue), not for existing bacteria to turn nh4 into no2.

Dead bacteria are usually a wash with replacements, like recycling, more or less. Die off releases building blocks and growing populations need an influx.

Right. Neither that conversion, nor the opposite conversion of nitrate into ammonia prior to incorporation of N into tissues, consumes phosphate.

 

[Miami Reef]

Can someone explain how nitrifying bacteria don’t use phosphates, if all living things require it? I never heard anyone saying nitrifying bacteria will be P limited.

 

[jda]

Organic tissue needs it to build, not function. New tissue needs new building blocks (nitrogen, phosphorous, sulfur, etc.). This is an over simplification, but if you are not growing then you don't need new building blocks.

Think of the building blocks as bricks and mortar in a building. Think of processing nh4 into no2 as the workers in the building. You only need new bricks and mortar when you are adding space to the building, not to work inside of it. ...again, an oversimplification.

Nitrifying bacteria doing nitrification things is not the same as growing new bacteria to be removed from the tank with organic carbon dosing. When you want to grow new bacteria, you need a bit of phosphorous (not necessarily phosphate), nitrogen (not necessarily nitrate) some sulfur, carbon, etc. to grow NEW ones. Growing bacteria can be limited without building blocks. Multiplication != function, in this example.

 

[Miami Reef]

Organic tissue needs it to build, not function. New tissue needs new building blocks (nitrogen, phosphorous, sulfur, etc.). This is an over simplification, but if you are not growing then you don't need new building blocks.

Think of the building blocks as bricks and mortar in a building. Think of processing nh4 into no2 as the workers in the building. You only need new bricks and mortar when you are adding space to the building, not to work inside of it. ...again, an oversimplification.

So ammonia to nitrite is basically like breathing for the bacteria? They aren’t using it to reproduce?

 

[jda]

Yes, to put it simply.

To make it more complicated, some of them could grab some nitrogen from the ammonia if they want to reproduce, if it can grab the other things like sulphur, phosphorous, carbon, oxygen and the rest of the building blocks that it needs, but this is a different process than just breathing. Different bacteria can use different substances to get nitrogen including ammonia, nitrite and nitrate.

To breathe, the bacteria need their substance and a bit of energy, which they can sometimes get from the substance - in this case nh4 but they need some carbon, IIRC (I am not a biologist or chemist, so going off of a bad memory). Nitrogen and phosphorous and not energy/food even though they get posted about as being reef tank food all over the web every day. They are bricks and mortar.

 

[GARRIGA]

To be literal. Bacteria don't actually breath. Correct? They chemically require oxygen which can be obtained from DO or bound oxygen. I make this distinction because it's hard enough conversing anaerobic vs anoxic depending on the background. Seems waste water treatment thinks differently than biology professionals yet I'm pretty sure neither think of it as breathing.

I could be wrong. My head is still spinning from getting a grasp on phosphorous where active workers don't need it although I believe they have a half life much shorter than real workers therefore new recruits constantly being needed which will need P and other things. More spinning.

These discussions are actually fascinating but often elicit four Advils after digesting the content. You guys are on a much higher level than self so excuse the lag as I'm constantly having to unlearn that just learned. Doubt I'll ever fully grasp why carbon doising works beyond it does and I think I'm content with that but ammonium feeding is something I'd like to get a good grasp on since it's something I plan on employing since first discovering it actually was a thing. Although I've known for a while plants prefer it vs nitrates which they need to down convert but wasn't sure how those dynamics work with corals. Seems that more I think of them as plants the easier this is getting.