DIY Ammonia dosing for low nitrate systems

[Jon_W79]

Is there any evidence for that hypothesis? Why would bacteria necessarily take it up faster than corals?

I don't don’t know if there is evidence that the bacteria capture ammonia molecules the way I described. One reason that I think that bacteria could have an advantage over corals for ammonia is that the bacteria could probably grow in areas with more water flow. I wouldn't really call it taking ammonia up faster than corals. I believe more water flow is an advantage. I talk more about it in some previous posts in this thread.

 

[spsick]

Randy, would you suspect Nitrate going up to result from regular Ammonia dosing? I’ve been dosing 12ml daily and nitrates have come up to 25ppm with no change in feeding or anything else. Would I be correct to surmise the corals are taking up the ammonia instead of nitrate?

I’m trying to figure out how to dial in my ammonia dose.

 

[Dan_P]

My hypothesis is that ammonia molecules get captured, even if the water flow is fast, by getting stuck to the nitrifying bacteria. The nitrifying bacteria don’t need to rapidly convert ammonia to nitrate to prevent corals from getting the ammonia if they have captured the ammonia molecules. If my hypothesis is true, I believe the dosing rate would matter.

It is tough to think about this.

When ammonium chloride is dosed to an aquarium, I would assume it is dispersed throughout the aquarium fairly quickly. The water has an even concentration of ammonium chloride. Ammonia oxidizing bacteria coating surfaces see only a fraction of the ammonium molecule as the water flows over the biofilm. They only see the bottom side of the water volume. The coral are bit luckier in that they are surrounded by the water, bathed in ammonium ion on all three sides. Just from the standpoint of the amount of time and surface area that is exposed, I am feeling that the coral might not be at a disadvantage for grabbing ammonium ion before the bacteria do.

 

[Red_Beard]

It is tough to think about this.

When ammonium chloride is dosed to an aquarium, I would assume it is dispersed throughout the aquarium fairly quickly. The water has an even concentration of ammonium chloride. Ammonia oxidizing bacteria coating surfaces see only a fraction of the ammonium molecule as the water flows over the biofilm. They only see the bottom side of the water volume. The coral are bit luckier in that they are surrounded by the water, bathed in ammonium ion on all three sides. Just from the standpoint of the amount of time and surface area that is exposed, I am feeling that the coral might not be at a disadvantage for grabbing ammonium ion before the bacteria do.

I would think that to be accurate, the real advantage bacteria has though would have to be volume if anything. More bacteria than receptive coral cells.

 

[Randy Holmes-Farley]

Randy, would you suspect Nitrate going up to result from regular Ammonia dosing? I’ve been dosing 12ml daily and nitrates have come up to 25ppm with no change in feeding or anything else. Would I be correct to surmise the corals are taking up the ammonia instead of nitrate?

I’m trying to figure out how to dial in my ammonia dose.

I cannot say what they are taking up, but dosing ammonia will raise nitrate if you are dosing more ammonia than organisms other than bacteria are taking up.

I’d likely back off on the dose so that nitrate stabilizes.

 

[Randy Holmes-Farley]

I would think that to be accurate, the real advantage bacteria has though would have to be volume if anything. More bacteria than receptive coral cells.

Several things seem important to me in such a competition between corals and bacteria:

1. Assuming ammonium or ammonia is actively transported into cells, then the affinity of these transporters for ammonia may be different.

2. The rate that these transporters actually deliver ammonia may be different.

3. The number of these transporters per square centimeter of exposed cell surface area may be different.

4. The cells themselves may become saturated with their need for ammonia at different rates and they may adjust 1-3 differently.

5. The total surface area is a multiplier in top of 1-3.

6. If uptake is passive, then only 4 and 5 matter.

 

[taricha]

In all the tank waters that I have seen - Mine, Dan's, a couple of LFS - ammonia processing is extremely slow in the water itself. 1 ppm of ammonia can last for several weeks in a liter of my tank water (even with movement). Add an established surface of any sort from an aquarium and the action is much much faster. Measurable ammonia consumption in hours. So hypotheticals about zillions of planktonic bacteria in the water column eating ammonia isn't very likely.

So let's presume most of the time that the vast majority of the ammonia consumption happens at surfaces in our tanks. So we need not worry that it "never makes it to the corals" even a tenth ppm of ammonia in water I am pretty confident it "makes it to the corals".

What they can do with it and how good they are at uptake is more complex - see Randy's points above on uptake.

If 90% of your tank surfaces are live coral tissue, even a small ammonia dose is probably getting mostly consumed by the corals. If 90% of your tank surface is nuisance algae - then worrying that you're just feeding the algae is probably correct.

 

[204Reef]

I was able to find ammonium carbonate rather than ammonium bicarbonate at a local store. It is labelled bakers ammonia, which is also how I've seen ammonium bicarbonate listed online. Can ammonium carbonate be used instead of ammonium bicarbonate? From what I understand it should have twice as much ammonia in it than the bicarbonate version aka: (NH4)2CO3 vs. (NH4)HCO3

Does this mean it should be used at half the recommended dosing volume for 0.1ppm or does it just decompose into the bicarbonate version in water and should be used at the recommended ammount?

Should the stock solution still be made at 20g per liter or something else?

This is the product I found:

Baker's Ammonia (Ammonium Carbonate)

Baker's Ammonia (ammonium carbonate) makes extra-crisp cookies or crackers. Great for handed-down recipes needing hartshorn. Buy at King Arthur Baking today.

shop.kingarthurbaking.com

 

[Dan_P]

I was able to find ammonium carbonate rather than ammonium bicarbonate at a local store. It is labelled bakers ammonia, which is also how I've seen ammonium bicarbonate listed online. Can ammonium carbonate be used instead of ammonium bicarbonate? From what I understand it should have twice as much ammonia in it than the bicarbonate version aka: (NH4)2CO3 vs. (NH4)HCO3

Does this mean it should be used at half the recommended dosing volume for 0.1ppm or does it just decompose into the bicarbonate version in water and should be used at the recommended ammount?

Should the stock solution still be made at 20g per liter or something else?

This is the product I found:

Baker's Ammonia (Ammonium Carbonate)

Baker's Ammonia (ammonium carbonate) makes extra-crisp cookies or crackers. Great for handed-down recipes needing hartshorn. Buy at King Arthur Baking today.

shop.kingarthurbaking.com

The weight fraction of NH3 in ammonium bicarbonate is 17/78. For the carbonate it is 34/94. This means there is more ammonia per gram in the carbonate, something like 0.33 v 0.20, very roughly 50% more.

 

[204Reef]

The weight fraction of NH3 in ammonium bicarbonate is 17/78. For the carbonate it is 34/94. This means there is more ammonia per gram in the carbonate, something like 0.33 v 0.20, very roughly 50% more.

So then should I use a lower weight when making a liter of solution, e.g.: 10g of ammonium carbonate rather than 20g of ammonium bicarbonate or just dose half the recommended amount e.g. 0.05ppm per day max? Or do either one and it doesn't matter?

Is ammonium carbonate more or less stable over time in solution, or does it not matter?

 

[Dan_P]

So then should I use a lower weight when making a liter of solution, e.g.: 10g of ammonium carbonate rather than 20g of ammonium bicarbonate or just dose half the recommended amount e.g. 0.05ppm per day max? Or do either one and it doesn't matter?

Either one.

Is ammonium carbonate more or less stable over time in solution, or does it not matter?

If the carbonate is more basic, there will be a larger amount of NH3 and greater NH3 loss. Maybe not an issue over several days.

 

[204Reef]

Either one.



If the carbonate is more basic, there will be a larger amount of NH3 and greater NH3 loss. Maybe not an issue over several days.

Hmm, that's something to consider given that I planned to mix up a gallon and dose it over several weeks to several months, depending on how the tank does with it.

I wonder how long it will last in a mostly-sealed container on a dosing pump (only mostly sealed to prevent a vacuum in the container).

 

[Randy Holmes-Farley]

I think it is ok to use, and as noted, is a bit less than twice as potent with a higher pH boost and no alk effect overall, just like the bicarbonate.

 

[Dan_P]

Hmm, that's something to consider given that I planned to mix up a gallon and dose it over several weeks to several months, depending on how the tank does with it.

I wonder how long it will last in a mostly-sealed container on a dosing pump (only mostly sealed to prevent a vacuum in the container).

If you had an ammonia test kit, you could add a bit to a sample of aquarium water and then measure the ammonia. You can get a sense of how much ammonia is being lost. I wonder if a pH measurement or an alkalinity test might also allow you to trend the potency over time.

 

[Drex]

Some reef aquaria have chronic low nitrogen availability. One indicator is very low nitrate. Nitrate dosing is a fine remedy, but it is possible that ammonia dosing may be more beneficial for some organisms since ammonia can be energetically easier to assimilate than is nitrate.

For this reason, I thought it would be useful to provide some DIY directions for ammonia dosing.

There are many materials that could be used for ammonia dosing, including some household ammonia solutions, but in order to give better assurance of purity, I'm electing the show directions using food grade ammonium chloride and food grade ammonium bicarbonate.

Ammonium Chloride
Ammonium chloride, NH4Cl is essentially ammonia (NH3) plus hydrochloric acid (HCl). The reason I mention that fact relates to the impact on alkalinity. Dosing NH3 followed by consumption by organisms to form tissue in a net alkalinity neutral process. I'm ignoring the fact that if it is converted into nitrate, alk is lost, because if that nitrate is later used, all the alk lost comes back.

However, the HCl that is effectively dosed will steadily deplete alk. Adding the equivalent of 50 mg/L nitrate (0.81 meq/L; coming from NH4Cl) will have depleted 0.81 meq/l (2.3 dKH) of alkalinity. That may need to be made up for in some other fashion, such as adding more alkalintiy supplement.

High quality ammonium chloride is readily available and inexpensive. Loudwolf is one brand, but there are many. Aim for food grade or ACS reagent grade. Amazon carries many Loudwolf is $7 for 4 ounces, which contains 38,000 mg of ammonium, and is equivalent to 131,000 mg of nitrate, enough to raise 100 L of aquarium water to 5 ppm nitrate about 262 times. So cost is not significant.

Ammonium Bicarbonate
Ammonium bicarbonate, also known as baking ammonia, NH4 HCO3 is essentially ammonia (NH3) plus CO2 and water.

As mentioned above, dosing NH3 followed by consumption by organisms to form tissue in a net alkalinity neutral process. The CO2 and water also do not impact alkalinity. Thus, ammonium bicarbonate is a net alk neutral way to dose ammonia.

High quality ammonium bicarbonate is also available from Amazon as baking ammonia. It is readily available and inexpensive. One brand sells 11 ounces for $15, so it's cost is similar to the Loudwolf ammonium chloride per unit of ammonia added (one needs to use more of the ammonium bicarbonate than the ammonium chloride, evening out the cost).

Stock Solution
Using either of these materials, we will make a stock solution for dosing. Keep it closed up as it will smell of ammonia and slowly loses ammonia to the air. Ammonium bicarbonate will have a higher pH, smell more, and lose ammonia to the air faster.

13.5 grams of ammonium chloride (about 3 - 4.6 teaspoons, varies by brand) in 1 L RO/DI water.
OR
20 grams of ammonium bicarbonate (about 4 and 3/4 teaspoons) in 1 L RO/DI water.

Both solutions contain approximately 4300 mg/L (4.3 mg/mL) ammonia, equivalent to 15,700 mg/l nitrate.

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.

I'd add it to a sump, if possible, to dilute it well before it gets to the main tank. Most folks dosing ammonia wouldn't also be using media intended to push the nitrogen cycle in various ways, but if you do, dose downstream of that media.

Of course, if anything seems to react badly the first time or two that you dose, stop dosing, double check the amounts, and perhaps come back to this thread for further discussion of what might be happening.

This article has a lot more on ammonia in reef aquaria, although some parts of it may not be correct (such as the utility of products such as Prime):

Ammonia and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

Happy Reefing!

Thanks Randy for your response

 

[Sebae]

Is there a daily limit to what one would safely dose? I’m currently dosing 1.0 ppm daily in a frag system and nitrate has yet to rise. My plan was to dose until nitrate started to jump up but nothing yet…

 

[Randy Holmes-Farley]

Is there a daily limit to what one would safely dose? I’m currently dosing 1.0 ppm daily in a frag system and nitrate has yet to rise. My plan was to dose until nitrate started to jump up but nothing yet…

I see no reason to think there is a limit aside from how fast it can be taken up, just as there’s no concern from number of fish generating ammonia until it was incredibly packed.

 

[Sebae]

Will ammonium chloride lose much potency over time? The powder I’m using is a few years old but has been tightly sealed. Just shocked by the lack of a rise in nitrate yet.

 

[Randy Holmes-Farley]

Will ammonium chloride lose much potency over time? The powder I’m using is a few years old but has been tightly sealed. Just shocked by the lack of a rise in nitrate yet.

I don't think the solid powder will lose significant potency. Water getting into it is likely the biggest effect. Ammonia and HCl leaving it doesn't really change potency since it lowers the weight commensurate with loss of ammonia.

 

[14A]

I've been dosing 0.4ppm of ammonia (ammonium carbonate stock solution as described by Randy, 0.1ppm four times per day) and so far so good. I'm still getting zero nitrates but growth has resumed and maxima's mantles more expanded.