Ammonium nitrate

[watchguy123]

what would be the cons to dosing ammonium nitrate to bump up nitrate levels?

 

[Randy Holmes-Farley Verified Community Expert]

You'd be bumping ammonia which is toxic. Unless you dose it very slowly, I wouldn't use it.

 

[watchguy123]

You'd be bumping ammonia which is toxic. Unless you dose it very slowly, I wouldn't use it.

Assuming ammonium nitrate is dosed slowly, as it dissolves in reef water wouldn't most of the ammonium covert to ammonia at normal reef water pH (8.2 or less). I presumed the ammonium would preferentially be taken up algae and bacteria and that little ammonia would stay as ammonia. The driving force being pH favoring ammonium over ammonia and the depleting concentration of ammonium via uptake.

I don't know how much ammonium a mature reef tank can process though without ammonia toxicity or simply ammonia caused deleterious effects

 

[drawman]

Why not use sodium or potassium nitrate as an alternative?

 

[watchguy123]

I am wondering if ammonium supplementation would be more helpful than just nitrate supplementation when nitrate levels test low for coral health/growth/color.

 

[Randy Holmes-Farley Verified Community Expert]

Assuming ammonium nitrate is dosed slowly, as it dissolves in reef water wouldn't most of the ammonium covert to ammonia at normal reef water pH (8.2 or less). I presumed the ammonium would preferentially be taken up algae and bacteria and that little ammonia would stay as ammonia. The driving force being pH favoring ammonium over ammonia and the depleting concentration of ammonium via uptake.

I don't know how much ammonium a mature reef tank can process though without ammonia toxicity or simply ammonia caused deleterious effects

Ammonium and ammonia are in instantaneous equilibrium. So it really doesn't matter whether you dose ammonia or ammonium from a toxicity perspective. The pH of the tank determines the instntaneous ratio of the two.

Yes, if dosed slowly enough it is no worse than a fish peeing.

 

[Juan Andrés Botero R]

You'd be bumping ammonia which is toxic. Unless you dose it very slowly, I wouldn't use it.

PaxBellum N+Mo -> is composed of Amonium Nitrate 5% wt/vol. Is it dangerous?

 

[Randy Holmes-Farley Verified Community Expert]

PaxBellum N+Mo -> is composed of Amonium Nitrate 5% wt/vol. Is it dangerous?

Ammonium nitrate is a fine source of N to a reef tank if it is dosed in a way that keeps total ammonia below 0.05 to 0.1 ppm. (IMO).

How much do you dose to what size tank?

 

[Juan Andrés Botero R]

Ammonium nitrate is a fine source of N to a reef tank if it is dosed in a way that keeps total ammonia below 0.05 to 0.1 ppm. (IMO).

How much do you dose to what size tank?

The daily consumption of the tank is 0.4-0.5ppm of Nitrate, to replenish this I add 5 ml daily of the PaxBellum N+Mo, The aquarium tank has 144 Gallons.

 

[Randy Holmes-Farley Verified Community Expert]

5 mL of 5% ammonium nitrate contains 53 mg of ammonia

Add that to 144 gallons (654 L) and the added concentration of ammonia is 53 mg/654 L = 0.08 mg/L ammonia (in addition to any ammonia already in the aquarium

IMO, that is pushing the level I'd want to see, and I'd split that up into 2 or more doses a day.

 

[Juan Andrés Botero R]

5 mL of 5% ammonium nitrate contains 53 mg of ammonia

Add that to 144 gallons (654 L) and the added concentration of ammonia is 53 mg/654 L = 0.08 mg/L ammonia (in addition to any ammonia already in the aquarium

IMO, that is pushing the level I'd want to see, and I'd split that up into 2 or more doses a day.

Thanks!!

 

[LimestoneCowboy]

Thanks!!

Is the residual Ammonia in a form that bacteria will just move to NO3 anyway?

 

[Randy Holmes-Farley Verified Community Expert]

Is the residual Ammonia in a form that bacteria will just move to NO3 anyway?

it is a form that many photosynthetic organisms will prefer to nitrate, and they may take it up before bacteria get it all.

 

[LimestoneCowboy]

it is a form that many photosynthetic organisms will prefer to nitrate, and they may take it up before bacteria get it all.

Great info, so net net, probably the best form of Nitrate to "judiciously" dose in our tanks?

 

[Randy Holmes-Farley Verified Community Expert]

Great info, so net net, probably the best form of Nitrate to "judiciously" dose in our tanks?

Well, emphasis on judiciously, yes.

 

[Juan Andrés Botero R]

Well, emphasis on judiciously, yes.

I also use Magnesium Nitrate; the extra magnesium is welcome, Any comments!

 

[Randy Holmes-Farley Verified Community Expert]

I also use Magnesium Nitrate; the extra magnesium is welcome, Any comments!

That's likely fine, but not as desirable as calcium nitrate. It raises alkalinity and not calcium, and makes a small but steady boost to magnesium.

 

[Taejin Sim]

괜찮지만 질산칼슘만큼 바람직하지 않습니다. 칼슘이 아닌 알칼리도를 높이고 마그네슘을 작지만 꾸준히 증가시킵니다.

I'm going to make Mg(No3)2·6H2O, but where does the alkali increase come from?

 

[Randy Holmes-Farley Verified Community Expert]

I'm going to make Mg(No3)2·6H2O, but where does the alkali increase come from?

Metabolism of nitrate adds alkalinity. 2.3 dKH for each 50 ppm of nitrate consumed:

From an article of mine:

When this nitrate proceeds further along the nitrogen cycle, depleted alkalinity is returned in exactly the amount lost. For example, if the nitrate is allowed to be converted into N2 in a sand bed, one of the products is bicarbonate, as shown in equation 2 (below) for the breakdown of glucose and nitrate under typical anoxic conditions as might happen in a deep sand bed:

(2) 4NO3- + 5/6 C6H12O6 (glucose) + 4H2O --> 2 N2 + 7H2O + 4HCO3- + CO2
In equation 2 we see that exactly one bicarbonate ion is produced for each nitrate ion consumed. Consequently, the alkalinity gain is 0.8 meq/L (2.3 dKH) for every 50 ppm of nitrate consumed.

Likewise, equation 3 (below) shows the uptake of nitrate and CO2 into macroalgae to form typical organic molecules:

(3) 122 CO2 + 122 H2O + 16 NO3- --> C106H260O106N16 + 138 O2 + 16 HCO3-
Again, one bicarbonate ion is produced for each nitrate ion consumed.